I have a Tempurpedic at home, and HAD a 4 inch memory foam topper that I put over the mattress that came with the Little Guy. I loved it. But the coldest I camped in was 40 degrees. I used a mattress heater to warm it up before going to bed.
Memory foam does get rock like properties when cold. I tried to try out a Tempurpedic in an unheated warehouse in Wisconsin during a below zero cold snap. Don't do that. It feels nothing like it will when in a heated room.
The Walmarche ones come vacuum packed in a box. They easily fit in the teardrop. Then, you cut open the package, and it grows large and fills out. I removed it a few times from the Little Guy. It'll scrunch up OK and go out the door.
I used a regular mattress pad on it. I do on the Tempurpedic too. I'm quite round and I do not sink in a hole in it.
Now I have a thinner memory foam topper on top of the cushions in my pointy trailer. It is also comfy. That is still thin enough that I can still fold up my trailer with the bed made. I give memory foam a thumbs up.
