I have no regrets,as they're a waste of time and energy, in life, there are no"do overs." If I had a choice, I'd like to spend my last moments with my lady friend, SaddleBaby, just enjoying each other's company.
I went down this path with my mother and my grandfather. I was with Mom up to the end.
I learned from those experiences that the question is somewhat specious: it would be a rare disease that kills us with a day's notice. And with those diseases (basically killing heart attacks that don't complete the job in the field) medical treatment pretty much precludes that sort thing. The soon-to-be deceased is surrounded by medical personnel trying to stave off Death for a little while longer.
Cancer and COPD are more slow-motion than this, and there is time to think about the end. My mother spent a lot of her time mending fences with family. My grandfather spent a lot of his time saying goodbyes. At the very end of these processes, I could see a steady deterioration in their attachment to the world. It appeared that their attention was turning increasingly inward. They left us more in stages than as a light switch.
All that said, if I knew I had months to live I'd assess my abilities (with my physician) and figure out which things on my bucket list were possible. Then I'd get together with my family and dearest friends and figure out which of the things on the "doable bucket list" are feasible and who wants to do them with me. At the very end, I'd like to handle it as my grandfather did: saying goodbye to those dearest to me, and giving them whatever I could that they needed of me.
Regrets? Yes, but I'm learning to let them go...
But my wish, and hope for all...
May you love as long as you live, and live as long as you wish