This is the Lucky Linden Tiny House on Wheels!
According to Tumbleweed, Meg and her husband, Dan, spent around 3 years and $25,000 to build it.
… the build took a lot longer than I wanted it to! Basically it was done in two or three chunks of time, separated by long stretches where very little or no work was being done. This was because we wanted to build the Lucky Linden without going into debt, so I would work on it when I had a stash of money saved up.3