I applaud your efforts.
As a child, I first moved overseas to the oilfields of Saudi Arabia when I was 7 years old and it really was life changing. My father was in construction so we didn't have any say in the matter. We just bounced around from one big project to the next. What you're trying to do sounds more stable and predictable.
Like you, I also wanted my children to have some experience living overseas so, when they were 9 and 11, I started looking for an opportunity to spend a couple years working overseas. All in all, I'm glad we did it but, many things did not go to plan and/or did not turn out the way I expected or hoped they would.
I made this decision not as a financial one but as a life experience decision. In terms of financial advancement, this decision set me back a decade (I was better off financially at age 35 than I was at age 45). In terms of cultural enrichment, let's just say that what I've learned and experienced can never be put back in the box. It is with me, always.
You can read all kinds of websites about expat life and there are organisations who specialise in training people for International assignments.
If you're thinking that $20K will be too much, frankly, you're probably not thinking big enough. Let me run down a few of the things that you will experience. I hope it works out for you but I do want you to know what to expect going in.
1. Moving Expenses Part I - Household Goods - When I moved between Los Angeles, California and Sydney, Australia, it cost me about $20K to ship my household goods each way. We did make the decision to ship everything. Kids bunkbeds, Lawnmower, Corps of Cadets Senior Boots, Fine China, you name it. In each direction, that also meant about 2-3 months of having no furniture. I Thank God every day since the Covid-19 crisis started that we moved when we did because otherwise, it could have been several months without furniture.
2. Moving Expenses Part II - Flights - Historically, booking one-way flights is going to be more expensive than purchasing round trip tickets but, right now with the low price of oil and the crash of the airline industry due to Covid-19, you might be able to catch some ultra-low fares. In my case, it cost us about $2,000 per person one-way to Australia but only about $750 per person back to Los Angeles 12 years later.
3. Moving Expenses Part III - Electronics & Incompatible Stuff - The power is different in Europe so the vast majority of your American appliances aren't going to work. Think about everything - Washer, Dryer, Television, Iron, Microwave, Refrigerator, alarm clock, portable fans, humidifier, Vacuum Cleaner, etc. By my estimation, that's about $10,000 worth of stuff going each way. Some things like laptops or cell phones will have auto-ranging power supplies so you can get away with just a plug adapter.
4. Transportation - You've probably got 2+ cars in the USA but might only be able to afford 1 car in Europe. They might have fees related to insurance, tolls, or the use of highways that you might not be used to paying.
5. Finance - Since you'll be new to the country, they might not want to finance a car for more than 3-4 years for you. When I went to Australia, 60-84 month vehicle loans were commonplace in the USA but in Australia, cars cost 2x-3x what they cost in the USA and the longest loan term I could get was 48 months. Vehicle leasing is illegal in Australia. So, forget about that $300/month BMW 3 Series Lease, you might find yourself in a 4-door SEAT (Spanish car) with a manual transmission for much more money than that.
6. Healthcare - As mentioned, they will have socialised medicine but you might be required to purchase private health cover as well. In Australia, the fine for not having private health cover was about $2,000 per year.
7. Taxes - Expect taxes to be high. Plus as an American, you have to file with the IRS. You also have to disclose any foreign bank accounts you open. Google FBAR
8. Time Zones - It is going to be very difficult to keep up relationships with friends and family due to the differences in time zones.
9. Schools - You will need to look into what kinds of schools are available and how much they might cost. If the public schools aren't up to scratch, you might have to send your kids to a parochial school, or a fully private school. When I was in Madrid last year, there was a very well equipped private school right next to the office where I was working. This school had armed private security. Your mileage may vary. I spent a fortune on private schools in Sydney.
10. Language - They speak a different dialect in Spain than they do in Texas or Mexico, etc. I had to learn some new Spanish words to communicate effectively in Spanish. The good news is that Castilian Spanish is relatively easy to pickup. Some Spaniards do speak a little English but it's few and far between.
11. Local Customs - The thing that drove me nuts doing some work in Madrid last year was the late lunches and even later dinners. Restaurants that didn't open until 8pm was just about to kill me. I realise this is part of the experience that you will enjoy.
12. Homesickness and Frustration - Everything from availability of goods, service, brand names that you know to sports (pre-Covid). These things can be frustrating if you focus on what you don't have. Instead, you've got to make a conscious effort to focus on what you do have and learn that things might be different but they still work. Just because they don't do it the way you are used to, doesn't mean it's bad per se. Just different.
13. Discrimination and fitting in - Just like moving anywhere, there will be people who don't want to help you because you're from out of town. The kids might get made fun of in school due to fashion or customs, or mannerisms. There will be a lot of initial interest due to their uniqueness. After that, it might be a struggle.
14. Visits home - it will be difficult to afford to visit the USA regularly due to cost and travel time. And you can count on approximately zero of your friends and family coming to visit you. In 12 years in Australia, my parents visited once and my in-laws never visited. Brothers, friends, cousins, classmates, aunts, uncles, etc. None of them ever visited.
15. Repatriation - Depending how long you're overseas, it might be very difficult to come home. In the case of your 16 y/o daughter, as far as Europe is concerned, she's already an adult in most respects. When you do come home to the USA, rest assured that almost nobody will understand what you've been through and what you've learned.
I stayed in Australia 12 years. I tried to pull the plug after 3 years and again at the 10 year mark. It took 12 years to really be in a position to repatriate.
I haven't talked about rental housing or getting a job but, I'll leave that to you.
In the end, I think it's worth doing but just be prepared for it to take longer and cost more than what you expected.
Good Luck!
