There are LOTS of choices out there for tall billowy grasses. Local climate will have a lot to do with which ones will provide you with the best winter showing. I will be interested to hear what other posters in your area recommend.
Some of it has to do with the structure of the grass. Molinias & Spodiopogon are 'almost designed' to fall over with the addition snow.
Some of the native grasses must be grown on lean/poor soil to be able to stand up to wet &/or snowy weather. (sunny exposure is a big factor as well)

I have gardened with grasses in zone 5 SW Ontario where we have 'on again, off again' winters with a mix of heavy snowfalls & freezing rain. Now I garden in a more northerly area with huge amounts of snow & that, always challenging, early snowfall that is wet & heavy.
What works the best for me?
#1 Calamagrostis arundinacea Karl Foerster - or any of the other cultivars are real troopers in all seasons
#2 Some Miscanthus sinensis cultivars. For winter durability & waving plumes, Miscanthus sinensis 'Roland' out performs all the others for me. This is surprising since it is a bit of a floppy grass until the culms dry off.

Not as much on the billowing but excellent winter interest:
#3 & #4 Panicum virgatum cultivars & Schizachirium sp. (little blue stem) provide fabulous winter interest.

A.

A late response, but I think the most gorgeous of all the grasses I grow is Miscanthus 'Morning Light'. And the most amazing thing about it is that even after it is absolutely flattened by snow or ice, when the stuff melts off, it springs right back, unlike any of the other grasses. One year it did it 3 times.

Also remaining upright except in extraordinarily heavy ice, is Erianthus ravennae, Ravenna grass. Little blue stem is also lovely when backlit, but if you have much snow, it will be covered up most of the winter.