I'm on the verge of a big buy and would like to run my plans by you guys.

I'm going to be buying a 20* burrow which I plan on putting inside my 15 Celcius (60*) synthetic bag if I ever get into the snow. This will only really be happening if I take a trip out of state as we don't really get below 5 Celcius in winter. Anyway, I'm quite comfortable with my pad at 10, 5 is a little cold but I can manage so in the interest of pure luxury, I was thinking of getting an UQ, and thought I might as well go for it all in case as I hate to be limited by my gear.

My question to you is, how hot would a 0* Incubator be comfortable? My other option is a 20* UQ, which would probably be perfect for the camping where I am living now, but would limit my choices.