My mother climbed Rainier in the early 60's. Tried and failed once, tried again and made it to the top. It was a moment she remained proud of till she died.
I've thought about trying it. But I would rather do it in 3 1/2 days or so, the whole deal where you climb all day, then sleep and wake up at 2 in the morning to hit the summit is a little extreme for me.
Load up on carbs before you leave, take ten cans of tuna, some crackers and coffee and it wouldn't be that big a deal.
I have a sleeping bag I got from Marlboro a few years back. Mummy bag filled with quallofil, rated to -10 or so, if it is over 40 degrees out, you DO NOT want to get into this bag! Trust me!!