So (variables such as trailer, axle configuration, wheel size and tire profile aside) it sounds like if I go for a 2.4m (94″) garage door opening I should be able to make it work, even with the under camper storage. Which is great.
Thanks all. I guess I made the classic mistake: stating a question instead of the problem I am trying to solve. I did this because I was actually trying to solve two problems at once, and who wants to bore people with extra detail?
So my first issue was garage door height, and I can see that that will have to wait until I have the trailer sorted. Fair enough and thanks again.
The second reason I was asking is that I’m thinking of buying a 270 degree batwing awning (to go on the car in the short term but eventually for mounting on the teardrop). There’s no point doing that if I can’t clear the rear hatch. So I guess my question should have been “How high above the floor of the camper?”, because that takes out questions of trailer, axles, and under-camper storage – all of which are relevant to the garage door problem, but none of which have an impact on this issue.