I brought a Catalina 270 from Missouri to Ontario using uShip. My experience was mixed. The first bidder was a crook. It cost me $500 and over four weeks of lost time. The second guy was great.
Do your homework. Research the bidder. Don't agree on any upfront cash. They will ask you for a downpayment (for the cost of fuel etc.). Resist as much as you can, and if you send the cash consider it a write-off.
Make sure that the bidder has a boat trailer; don't agree on having it hauled in a cradle. It might be cheaper, but it may hole the hull.
Before you decide on anything, check the professionals (e.g. Andrew's Trucking ?? of S. Ontario (Hamilton?, Mississauga?). They will cost more, but they really know what they are doing.
good luck
Marek