Another tip on cold weather camping. We tailgait during college football season and spend a few weekends each year in sub-freezing weather. One of the absolute BEST purchases we made was a heated mattress pad. They're inexpensive, and even if you use a small generator like we do when we're tailgaiting, they hardly use any measurable wattage.
If you have a memory foam topper like we do, you'll want to make sure that you have something between the foam and the heated pad. That's pretty simple as well. We put the foam topper directly on top of the mattress, then put another inexpensive mattress pad/cover on top of the foam, AND THEN put the heated mattress pad on top of that. The bed sheets go directly on top of the heated pad, and with a 15 minute "pre-heat," our bed is toasty warm, even when temps drop to 15 degrees.
Here in the Northwest, we sometimes camp at altitude and/or in areas with dense tree cover. It gets chilly at night, even in the summer. The heated mattress pad is fantastic and it allows us to turn off the furnace at night.