think Cabellas or LL Bean had a camp cot , with an insulate layer suspended under the cot
to keep body heat from going away from beneath, similar situation for a hammock in cool weather


Closed cell foam pads are almost non compressible , but wont be any smaller when packed for travel either .

I have a down filled air mattress bag that does the ground insulation thing well ..

3 parts, they use a double layer of tops and if colder you use them both ,

or the thicker or thinner depending on the temperature..

RWB, camp in the back yard , bring a thermometer with you and run the test yourself.

I dont find that without a compression sack they will compress well ..
GooseDown is the best compressible insulation others to try to match..

they are a fuzzy sweater essentially there is a moisture transfer treatment to the polyester