Never worried about it until last October when we purchased the new 5er at 13 feet 4 inches tall. Before that, had travel trailers around 11 feet tall.
The day we brought the new 5er home I parked in the same spot where the last TT sat. After I got in, unhitched, and set up, the neighbor came over and said he saw me back in and said he was going to yell at me because that 'thing' on the roof of new 5er was hitting "low hanging" tree limbs. He didn't yell because he was too far away, and the sound of my diesel would have drowned out his yells anyway.
Well, I looked up and sure enough, that small television antenna was in the small twig type branches hanging down. I had them trimmed up OK for the 11 foot tall travel trailer, but the extra 2 feet on the new one put the air conditioner and the television antenna right in them. Fortunate, they were jsut the small twigs with lots of leaves.
So, I got the tree saw out and climbed on the roof of the 5er and trimmed up ... again ... as high as I could reach. I had to re-hitch the trailer so I could move it so I could get the rest of the tree, just to make sure everything was trimmed up REALLY good.
First time I pulled the camper out from under that tree, the tree sure looks funny now! It's trimmed up so high it crazy. But, I look at it every day now and have focused in my head how high of a clearance I really need for the camper. When traveling now, I'm very, very much aware of the height, where, when I had the travel traielrs, I never though out it.
Yea! It's a life adjustment in your driving skills ... for sure!