I'm not super familiar with EPD's assets, but as a midstream company, the vast majority of their revenue is fee based. Think of them like a toll road for hydrocarbons. If you think their traffic will stay the same or increase, you should probably hold. If you think traffic will decrease, sell.
Since midstream companies have become more fee-based businesses, they are not as sensitive to underlying commodity prices, but ultimately, their volumes will be sensitive to commodity prices.
I've mentioned on this forum my attraction to KNTK over the last couple of years and I am also at a decision point to sell or hold. The stock is up ~95% since my entry, plus I have received ~20% of my basis in dividends. They currently have a high P/E relative to some of their peers, but their earnings continue to grow and they have a very attractive optimization project in progress that should further help earnings. I think they are an attractive target to larger midstream companies that would like to enter or expand their presence in the Permian. I just don't know what the acquisition appetite of those companies are. Today, I'm a buyer below $52 and a seller above $62.