In that case, I can highly recommend
this.
I've had the previous version of it for about 4 years and it's done quite a few camp outs.
You can forget about any form of insulation in it, but I solved that issue with a cheapo emergency foil blanket (which would be handy in an emergency situation anyway) between the mat and ground.
It isn't self inflating either but that keeps the weight down and the self inflaters that I have tried in the past were useless and needed blowing anyway. It doesn't take long though.
Mine packs up to about the size of a coke can but it looks the newer model might be a teeny bit bigger.
The only mat that might be better I think would be a thermarest of some sort, but they cost a fortune and are prone to delaminating. So I've heard.