Re: What is the maximum size for a boat if you really want to trailer it?
Well the OP hasn't responded back to any of the responses so maybe he's just taking it all in...
To the O/P - The size of the boat depends entirely on your situation. Can you tell us a little more about what your resources are for towing and maybe the routes you need to take to the places you plan to use the boat most. If its the restriction to one boating area that leaving it in a slip has you feeling confined but you like the creature comforts of a bigger boat then we need to know what sacrafices you're willing to make to get yourself out of marina slip jail.
If it's just a matter of money and paying for a slip is difficult now, then you need to consider the fuel costs when towing a big boat. My F350 6.4L Diesel got 6.2mpg from San Francisco to L.A. with a 40' in tow. My buddies F450 got the same as well as another guys F550. We all pulled Off Shore boats. I didn't even add it all up for fear I'd have a heart attack. I was happy I got to use the boat but after I filled it up with fuel and paid for the week's stay, etc.,etc.,etc., It was a pretty expensive run.
My biggest pleasure boat now is a 22' North River Commander with a 8'6" beam and it's come to the point that I don't enjoy hauling it and launching it by myself anymore. My favorite is one I bought last year, a 16' JetCraft. However, if I had it my way, they would all be in slips all year round. When the old life speedo starts pinging on 60, towing and launching seem to be the two worst parts of owning a boat. Thats just my own opinion.