TheManOnTheBus, you'd struggle to find anywhere with space for 22 people to cook and eat together, but if you'd be interested in somewhere where you could rent a range of apartments (one sleeps up to 13 and would be very cheap if all occupied) in a building with a big communal area, ping pong table, space for kids to play, table for adults to sit round with a glass of wine and a bowl of peanuts, this might be of interest.
http://www.chalet-bisanne.com
I am organising a big party there at Easter next year. Right next to chairlift, as you can see, and also there's a free rope beginners lift. The apartments are quite roomy, by French standards, not luxurious but clean and well cared for. The tarifs on the website are still last year's. I have this year's, from the managing company - they're just up a little but still good value.
It's the big building just to the left of the piste. Ski and boot room at the back - walk out onto the piste, or easy access for kids to play in the snow, safely off the piste.
After ski hours there's good toboganning for kids. 185kms of lift-linked pistes. Small supermarket, restaurant, ski hire shop, all very close.