I actually camped on top of the falls.
There was not many people in the valley, and zero people on top of the falls. I was cutting my own trail through the snow on top, so no one had been there in a while. It's a great time of year to visit to avoid crowds and mosquitos. The roads are plowed, but they were requiring snow chains for all non-4wd vehicles. That changes daily though.
I suppose you could camp at "camp 4" (bus stop 7) and then day hike up. There was zero people there last I saw, and it and gives you easy access to the falls trail. Traction is a must, and snowshoes make life easier if you get all the way to the top. The video probably makes this clear, but definitely be prepared for cold and falling ice.
Here was my layering system that I was still cold in:
Arcteryx phase SV
Patagonia R1 hoody
MH monkey man jacket
Montbell Alpine light
Arcteryx alpha SL
Northface Fleece pants
Arcteryx gamma lt