I bought a rubber roll up mat 4' wide sold at princess auto. They charge by the foot. The mat I purchased is heavy nylon backed on one side with a non skid check plate stamp on the other.
There is a "lighter duty" version - but I wanted the heavy material to add cushion and added insulation.
http://www.princessauto.com/en/detai...at/A-p8397325e
I Purchased 2 pieces about 10' long that roll up nicely, roll out easy, insulate the floor to keep the feet warm and the condensation down for my 8 x 8 tent.
They don't freeze up and stick to each other (or itself) nor does it get memory (stays stiff when tightly rolled).
Works awesome ...... highly recommended.