Hi. 2NavyBrats
I'm new here and I don’t own an HDT yet but I have been doing a lot of research since I’m a working truck driver and my plan has been to semi-retire pulling my travel trailer with a day-cab truck. Life is holding me back a bit right now.
That being said, if you have the 2 door JK it is just under 13’ nose to tail stock. The 4 door is 14.5’. You can find trucks of various lengths but a common back-of-cab to tail-of-frame is 13’ on a 3-axle truck (that is steer axle plus 2 drive axles). If you have the 4 door you’ll have to do some measuring on different trucks to make it fit. I have been planning the same thing but with an older Wrangler and pulling a travel trailer instead of a 5th wheel so there’s no conflict.
I'm not sure how much extra frame length you’re going to need between the rear of the Jeep and the front of the trailer for cornering but I assume it would be at least half the width of the front of the trailer. Just to be clear, the Jeep will have to load from the rear instead of the side because it’s too long. So just off the top of my head the cab-to-tail length would have to be at least 18’ for the 2 door and 19.5 for the 4 door (which I assume yours is because you said “JKU”). That’s if the Jeep rolls right up to the cab. Weight isn’t a problem because they only weigh around 4000 lbs. Total weight to the ground on a single dually rear axle on these trucks is 20,000 lbs. On tandem dually axles it’s 34,000 lbs.
I'm just thinkin' here in the middle of the night so take my figures with a grain of salt.
Hope it helps.
Chevy