I have a B2650 with FEL and backhoe on the way and I'm planning/hoping to haul it on my 16' landscape utility trailer. A couple people on here confirmed that they make it work, I even have a picture saved from one of them. Definitely requires swinging the backhoe to the side though, so I don't know if it would be doable in a dump trailer or not.
I checked one out at the dealer earlier in the summer, they swung the backhoe sideways for me so I could measure. It was around 14' I believe from the front of the bucket to clear the backhoe in the back, maybe a hair more. So I figure I'm not going to have much of any weight distribution room to play with. I'll see how it works though, hopefully won't need to upgrade to a longer trailer.
ETA:
Here's a pic of a 16' tape next to it with the backhoe swung all the way to the side. The end of the tape is at the front of the FEL bucket.
And here's someone's B2650 on a 16' landscape trailer. Don't remember whose this was, but if the owner sees it, thank you again for posting.