Thanks Akichow. Of course as I get closer to the date in Sept I will be able to judge how fast I will go, with the orthopedists blessing of course. And my hubby and hiking buddy have agreed to take the extra weight I will not be able to carry (although my buddy said I should just take less food lol).
Have you thought about where to camp, Outpost Camp v. Trail Camp? I've done both, and I think it is a tough call (though some others on this board will probably have strong feelings for one or the other). Outpost Camp is lower and prettier, and if you do the summit push from there in one day, you don't have to carry your backpack up to Trail Camp (some folks think that the section between Outpost Camp and Trail Camp is one of the toughest sections). You'd probably sleep better at Outpost Camp, too, because of the lower altitude, and it can be less windy. But, doing the summit push from Outpost Camp adds a lot of mileage to the day. I did the summit push from Trail Camp last Labor Day, and was glad I did.
If you do a third night, that is more food to carry, and more weight. You really want to keep your backpack at 25 lbs if you can (including water). It is doable. More than 30 and you may find yourself in trouble, even if you are in excellent condition.
You can find my trip report from a 2 nighter over Labor Day here if you are interested in how our group of 3 women did, and how weight may have factored into one woman's difficulty (despite the fact that she was an experienced backpacker in excellent shape). Also pictures.