I won't be backpacking, so i'm not concerned with weight, but I have to think of space. I have a short wheelbase Jeep Wrangler. I need to fit all the camping gear, hunting gear, and my dog in it. Plus have some room for meat if I get an elk.
I'll use the gear for some mountain fly fishing trips too, but it will be in the summer.
I checked the weather for that area during the ML season this year. The lows were 20-40 degrees. I can handle that ok with just a tent and sleeping bag. Knowing my dog. He'll be snuggled right against me. That will be my heater.