JonW, I have no experience, yet, cooking in a thermal cooker. If you want to cook a smaller portion you can fill one pot with the ingredients for your meal and the second pot with hot boiling water. Or prepare your main dish in one pot and a side dish or desert in the other pot.
I look forward to learning how to cook well in a TC. I think I'll enjoy cooking in it, eat better, and save $$ because I will not buy pre-prepared food or restaurant meals as often.
first edit: some people make a lunch sized meal in a smaller thermos. Amazon has reviews with ideas for them too. I think someone wrote about that idea earlier in this thread too.
second edit: I'm going to IRG 5.0. I plan to use my new thermal cooker there and to bring it to the pot lucks. Maybe, by then, there will be some more TCs there too. I searched Joanne's Camp-CooK web site a month or more ago. There were no results I could find for a thermal cooker from the users of her site. Maybe that will change.
third edit: I did not think to look for a discount code for SaratogaJacks. Ooops. I usually look for them when I am planning to buy something online. Retailmenot is usually the best place I have found for current discount codes. chefbrad.com/Saratoga_Jacks_5.5_Liter_Thermal_Cooker has a 10% off discount code.