The place I am working with can do higher than 12 foot legs but it substantially increases the costs, because anything taller requires different engineering and two legs in each position. Right now a 24x30 carport in 12 gauge steel with 29 gauge roof is around $4600 installed (built and bolted to concrete pad). As long as there is room to bring the trailer in ~ 1 ft from the leg - which I need anyway so as not to cut it too close when backing in - it should fit.
I remeasured my trailer. It is 26’ from end of the tire to front of the nose. The hitch is another 3’. So 30’ covers the tire and covers the hitch and still leaves me another foot of room.
What do you think? Am I going to regret this? We aren’t going bigger! Our next camper will be a truck camper if anything. When the kids go off to school this will be too big for us and we’ll downsize if anything. Full timing is not in our future, not for 20+ years LOL. The problem is anything longer than 30 feet really starts to cut into my backyard, and becomes visible in a way I don’t want with the landscaping plan we have. In some vague possible future I guess I’d rather have a couple feet of RV sticking out the back end of the carport than living with the whole shebang visible from my back porch and pool area every day for the next 20 years.