OK, I have been looking at insulated beverage containers. Popular Mechanics did a review of a couple dozen, testing how well they minimize heat loss over 24 hours with hot beverages, as well as how well they minimize heat gain over 24 hours with cold beverages.Insulated containers have gotten really great over the past decade. I carry a HydroFlask of hot coffee with me for my coaching duties which often take place in sub-freezing shade and it keeps the coffee hot for many hours. Similar containers from Yeti, Kleen Canteen, Manna, and others work similarly well. My 20 oz. HydroFlask fits in a jacket pocket, tho I wouldn't carry it like that for more active skiing. But if you take a light backpack (and I'd think many people will pivot to this model for the coming season given... y'know)? Gold.
https://www.popularmechanics.com/adventure/outdoor-gear/g3089/best-thermos/
I'm thinking of sticking one in my pack and debating between 18-20oz and maybe 28oz, definitely not 36 oz. I'm liking the idea of the Otter Box with a thermal top but those things get more expensive.