While going down the road today, I thought about this dilemma. Here's what I have come up with for a way to get an RV, daily driver, and a C-Dory all to one place at the same time...
Buy a motorhome with at least 10,000 pound towing capacity, in the shortest length possible, 34-35 foot diesel, perhaps. Get a smallish truck, like the Nissan Frontier. Set up the truck with a front tow bar to tow it behind the motorhome. You will now be limited to a smaller C-Dory, but I think the Frontier would handle a 22. Tow the boat behind the truck, hooked up to the motorhome.
35 foot of motorhome, plus 17 foot of truck (plus 3' of towbar), plus 25+ feet of boat on the trailer... you're at 80+ feet. :shock: This is going to be over the towing length in almost every state...
http://www.towingworld.com/articles/TowingLaws.htm
So, stay out of the west coast and east coast states, and you may go "un-noticed." If you need to shorten up, it's easy to unhook the truck with the boat hooked to that and drive separate.
Of course, you could try to find a shorter motorhome/truck conversion that still has the necessary towing capacity, and/or go with a shorter model C-Dory. Like most things, it's a compromise.
Then, there's the other option, if money is no object: a toter-home/big ass trailer combination...
http://www.truckconversion.net/
http://www.cowboycadillac.com/classa.htm
Add a BIG trailer that could accomodate a C-Dory on a trailer and a vehicle.
http://www.flyingamotorsports.com/
http://www.renegadedirect.com/
http://losangeles.craigslist.org/lgb/rv ... 01715.html
Overkill, perhaps? Just an option.