If its any help our track is only about 10 foot wide with stone dyke walls but we got a 12 foot static in.
How....well if you get a proper transporter company to do it, the truck bed they lift it onto takes it above the height of the walls - so if walls are the issue they might be able to work round it, altho not if overhanging trees with big boughs across.
We were just going to get 10 ft but the extra 2 feet makes a lot of difference, because it means you can have dining one side, kitchen the other, and a big wide seating area with a good size coffee table, whereas the 10 foot ones (the ones we saw anyway) had its different living zones along the length , which made them seem a lot smaller.
We did the drainage first, even before the static arrived, so it could be plumbed into the new septic tank, which makes life a lot easier if you can do this.