Welcome to ribnet!
Sounds like a good old SR4 would be bang on. Something like that won't need a braked trailer (unless you are driving a Vauxhall Corsa or a car of that ilk!) , which instantly wins you about half a metre "Road LOA".
If you can live with dropping the engine every time you get home (as I have to) then as long as you don't get one of the oldschool long throw 2 cyl engines (that poke out a mile behind the transom), I bet you could get it in. The SR4 has fairly long toob cones, so the chances are your engine won't be sticking out much over the tip of the toobs.
If it helps to put things in perspective. I have a 5m boat on a braked trailer in a 5.7m garage, I have carpet down the back wall, and the engine needs to be both down & hard to port or stbd, then pushed hard against the carpet. At which point I have 1/2" clearance to the door panel. (if the hitch is in line with the door's frame it won't close!)
A trailer with an adjustable drawbar is kind of crucial unless you have done a LOT of homework first!
Food for thought. I'm sure others will be along soon with opinions on makes & models....