What size mat is best for sleeping? Can I sleep on my mini mat?

You can sleep on the Mini Mat, and it will warm you up, but the size of the mat really matters. 

The smaller mats are not as good for sleeping because of their smaller area, and because the edges are noticeable, you may feel uncomfortable.

Usually, the Compact Pro 24"x59" model is ok for smaller folks, but the Pro  29”x73” mat should be chosen for bigger people. The Single size mats 39"x75" are best.

Queen mats are unique and very rare. They allow the temperature to be adjusted separately for each of the left and right sides of the mat. It is the best choice if you share a queen bed with a spouse.