One limitation that's specific to me as someone with MCS is that I can't drive a truck with a diesel engine. Diesel powered pickup trucks can pull almost twice the weight that gasoline powered ones can, but the fumes are extremely toxic, linked to lung cancer, and I have a specific liver enzyme malfunction that makes me extra vulnerable to diesel.
Biodiesel that's actually 100% vegetable, instead of a mix of diesel and vegetable fuels, is very hard to find, and in most of the world, feeding corn to engines instead of people is considered a crime against humanity. I don't have the physical stamina to collect and convert used fast food oil, so until there's a viable alternative, I'm stuck with gasoline. The best I can do is to plan my travels carefully, so I'm not zig-zagging around the country, and keep my vehicle in good shape, so it's burning as cleanly as possible.
But what that means for my trailer is that every single ounce counts. What frying pan I choose, whether I keep hardcover or paperback books, what wood I use for my bookshelves, how I heat my water (tank or tankless)--in fact, every decision must take weight into account.
My frame, outer walls, trailer, doors and windows and built in storage will weight around 6000 lbs. That's not counting the insulation, inner walls, subfloor, flooring, counters, bookshelves, appliances, furniture and belongings. My old journals will need to go into storage because I can't afford the ounces to haul them. The three plants I plan to bring have to go into lightweight pots. I'll bring only the tools, books, kitchenware I most need, and leave the rest.
I knew I'd need to thin out my possessions because of size and weight limitations, but the inferior pulling power of gas is raising the stakes. So I'm keeping my scales at hand.