Ostrander Hut holds 23 plus the hutmaster.
Snow Creek Cabin is much smaller. I think there were only eight of us total the last time that I was there, and it filled the place. So far this year, the snow is shallow, so you can probably find the place, assuming that you pick the GPS coordinates off a good map and then follow that.
Snow Flat Snow Surveyors Cabin is small, also, and it takes a master key to the park to get in there. However, it was very cozy.
Parsons Lodge at Tuolumne Meadows was big but drafty and hard to heat up by a fireplace. Getting access is tricky. There is a naturally carbonated spring within a short walk from the door, so bring some beverage powder.
The Tuolumne Meadows Ski Hut (a.k.a. the campground office) used to have room for about eight or ten, but it is first come, first served, free, always open. If it is full, you can snow camp behind the building and step inside to warm up if you are really cold. Been there, done that.
There are other smaller places, but they are either very hard to get to or else very hard to find once you get there. Plus, some are 120-year-old miner cabins that are falling down. They are better than nothing, depending on what the weather is like.