Thank you for your service.
I used to have a fiberglass trailer and would frequent fiberglassrv.com website. They have a number of members that full time in the smallest of trailers like a Casita and love it and wouldn't upsize for anything. I watch the home channels and see couples that want to live in tiny homes and seek them out. Some are drawn to a minimalist lifestyle and don't want to be burdened with the stuff. Each to their own. I hope you find something that fits your needs perfectly.
If you want to tour the country I would pay close attention to the specs. If you are going to tow, park and live then maybe bump right up to the limits IMHO.