Dear "Spirited...",
I donated at age 56, 14 years ago, and recovered well. I think that the key is to keep your plans "tentative". I have read many recovery stories over the years and there is a GREAT deal of difference among donors. Some get back to normal quickly, while others report serious long-term difficulties. So it is wise, I think, to keep lots of back-up plans ready just in case you don't recover as quickly as you hope. In particular, have a list of people you might call if you need some help. Maybe even let them know ahead of time and ask If they would be willing.
My own surgeon recommended that I start gentle bending and stretching exercises the day after surgery. And I donated by the open method, so had a 10-inch incision along the flank. He said that bending and stretching would help it heal well, and it did. BUT, he said to bend only until I felt pressure/pain at the incision, then stop and hold that position a few seconds before relaxing. Better to go too slow rather than too fast.
Before trying a 2-day hike please take some gradually increasing shorted walks to make sure you can handle it.
Best wishes. Please let us know how things go.
Fr. Pat