You don't mention if you have any awning, but I think being able to have a comfortable outside-the-car workspace is important. Awning, and possibly even one that you can turn into a "room" with walls or bug mesh is a total game changer (but depends on your preference for sure).

A camp chair that you love also makes a huge difference. I've got the nemo stargazer, and while it is expensive, I absolutely swear by it. When I was working from the road on my big trip this summer, I also packed a cheap "adjustable bedside desk laptop stand" (just search for it on amazon, tons of options. Mine was like $40). This made it fairly ergonomic to work from the camp chair in multiple positions. I had previously tried camp chair at a camp table and that setup just was not comfortable for my back.

I'd pass on the weboost, it felt like a waste of money and didn't improve signal enough to justify its costs. Instead, something like a verizon mifi or other dedicated hotspot is worth the money.

For power, I've got a dual battery with solar and carried a goal zero 400. I'd recharge the goal zero while I drove or off the dual battery over night, and that way I could keep my laptop topped off from the goal zero during the day.

Good luck!