I currently have a 24' x 8.5' enclosed car trailer, we had 7 H14's, and H16's in NY last year. If packed correctly I think we could have gotten at least another two boats in there.
My current work trailer is a 7'x16' with a flat nose. When it comes time to replace that I'm planning on getting a 8.5'x18' w/ a 7' wall, ( I hate hitting my head), and with a V nose. My hope is that I can build a rack for my boat and then just slide the rack and boat into the trailer at an angle. It'd be nice for doing events in the winter when I don't want the boat to get beaten to death with sand and salt from the roads, plus as someone else mentioned you can sleep in it as well.