Using a different set of "storage wheels", why not just let the camper sit on them over the winter? You are planning on taking them off anyways when you use the camper.
The way I mess things up, I wouldn't raise the camper back up to "normal" height once in storage... When pulling out in the spring, I would forget that I did that and would damage things pulling out.
Seems like a lot work here. Raising the opening height of the garage / barn door is not an option? It may not be as expensive as you think, compared to everything else you are planning.