Cots in portable question

I sleep in a portable from time to time. I almost have all the kinks worked out. My one question to guys who have done similar is this,

Do you use anything between sleeping bag and cot canvas? If so, what the heck is it? I’ve tried a therma rest and seems to work just ok. Just seeing what you guys use. The cold seems to come right from under the cot. Any suggestions very much welcomed.

Also, Mille Lacs is slow slow slow. Went out of Randy’s and got a 26” 23” 19.5” and 13” that was it for the trip.

Back in my younger days when we went to Canada, lake spiwisk, to be exact I was told to bring 2 sleeping bags. Lay one on the cot like a mattress and crawl in the other on on top.

We camped for 5-6 days on an island 60 miles from our vehicles.

Put your Mr. Heater cooker under the cot face up that will keep you warm lol

I do what glen said with 2 bags. Never had a issue.
I fished out of rocky and had the opposite. We did good Friday and Saturday. Slow Sunday.
To much pressure. We went to bed Friday with 3 shacks near us. Woke up Saturday to 50 near us. Kind of hurts the bite

You do need to worry about the heat loss out the bottom- the insulation in your bag gets compressed. When we camped out in Boy Scouts in snow caves, I would use a thermarest and a 1/2 inch closed cell pad under me. A Thermarest is pretty good by itself, depending on which thickness you have.
There are now down filled air mattresses, but I assume the weight is not an issue, so go with a good thick foam mattress, (or 2), either closed cell or open cell filled air, like Thermarest.

What about using a piece of refletix under your pad? I plan on ice camping for the first time this year, my plan was a piece of reflectix then thermarest then my sleeping bag. I’ve never heard anybody mention refletix used for this but it certainly seems like it should help reflect the cold from the ice back down, and reflect your body heat back up toward you?

Foam is the way to go in the winter.

I leave my more comfortable self-inflating pad at home.

Air pads suck the warmth right out of you in the cold, even ones with some padding/insulation in them.

If you have room, bring both and don’t put any air in the self-inflating.

Odd as this may sound…. My last 3 outings I used a large moving blanket. I folded it once and laid this between my cot and sleeping bag.

I happen to have the moving blanket in quick view as I was packing for a outing. I looked at it and thought what the heck, I will give it a try. I have no complaints after 3 outings so I will be using it on my 4th as well.

I used a therm-o-rest and my wife’s workout mat on the cot and then a -15 sleeping bag. Froze my a$$ off but I wasn’t using a heater while I “slept”