Betsy, I have a Thermal Cooker that I bought to use while on the road with the fifth wheel. It beats a slow cooker and while traveling with the Tear or Raindrop it would be a dream.
It has an inner pot and an outer pot. The outer pot is the insulation. When camping, after breakfast you put your ingredients that you want in (like a slow cooker), bring them to a rolling boil, put the lid on it and set that whole pot inside the insulated outer pot, close and lock the lid, set it in the floorboard of your car or even inside the trailer - no electricity is needed! Leave in the morning and when you arrive at your destination after a long days drive, you've got dinner ready!
I do chicken and rice and a roast in mine - with taters, onions, carrots and all. What I can't figure out is, the taters and carrots are done, but not mushy and the roast is completely cooked! I have a great roast recipe if anyone wants it - gravy included, so all you do is open the pot and dig in!