Spent a good chunk of time there. Was lucky to be with some locals so wasn't totally out on an island.
Big university there so you got a lot of foreign students and expats.
Some of the smartest science people in the world come out of Debrecen.
Driving there is a challenge if you ain't use to it.
Thermal baths were great.
To get anywhere via air its a good drive to Budapest.
Nearest comparable place would be Brno, CZ
Hinterlands outside of there is a wild place and gets dark fast.. A lot of gypsies so look into that issue.
Would def spend the money to go out and visit for a least a week to get a feel for it.
You talking several years, would rank it as one of the tougher places to live as an expat. Being an expat sounds fun but it will wear you down.
Gut feeling is that it would be an adventure, but would also be a grind.