I am doing a drop camp first rifle season in the Flat Tops. Looking for any recommendations regarding the the proper rating for a sleeping bag or quilt given that we will be in a canvas tent?
I have a zero degree down bag I got from Hyke and Bike on sale. Is very light, very compact and was really reasonably priced for a down bag. Previously I had 20 degree bags but they were not down so were heavier and more bulky and not as warm. I've never been too hot using it. You can always unzip and just lay on it if too warm. That said a zero degree bag is supposed to allow you to survive at zero degrees but not necessarily be toasty warm at that temp.
The flat tops are pretty high so expect pretty cold temps at night. Possibly Teens I would imagine or colder. I was up there one year in bow season and it was cold (below freezing) at night in Sept. I would go with a zero degree in your shoes. If they don't supply cots get you a decent R-rated mat to lay on so you will be insulated from the cold ground.
IMO don't count on your tent or stove to keep you warm. Even if they supply cots, you need insulation under you. Your pad is as important as your bag, and your bag's rating is dependent on a pad providing insulation. Keep in mind a cot elevates you and allows air underneath. So if that air gets cold...
Aaron had a recent podcast, January 9th, all about bags, pads, and staying warm. I would go over to Kifarucast and give it a listen. He breaks it down nicely so you can make the right choices not only buying it but using it as well.
We've done quite a few 1st season drop camps (going again this year). 0 degree is the way to go. The first year I went I used one of those light weight 10 degree, overly expensive, high speed backpacking mummy type bag. Every time I rolled over I was getting twisted up. The next year I bought a 0 degree over sized flannel lined bag and haven't looked back. It gives me room to roll around, I can keep some clothes in the bag with me so they're not so cold to put on when its early in the morning, and i can get dressed while still in my bag. If you're doing a drop camp and getting packed in by horse, weight isn't that much of as an issue. Be comfortable if you can be, drop camp hunting and backpack hunting are two different ball games.
I would probably want a zero degree bag as I have seen feet of snow that time of year but not necessarily sub zero temps. Insulated pad will be key as well.