Call up a mobile home mover. If they can't get the boat and cradle on a trailer it can't be done.
I've moved my Triton three times, twice with a flatbed, once with a professional mover. Once with my buddies who work at a mobile home service, and once I put it on a flatbed alone using a floor jack, a bunch of wood for cribbing, (from the mobile home service) and some pipe for rollers. Here's the Triton and the cradle:
Picasa Web Albums - ken - triton
I just lifted it a bit higher than the trailer with the cribbing in front set back a bit, then pit the pipes down on the trailer, set the front of the boat on it, then pulled the cribbing in front and pulled the trailer back with a pair of come-alongs. Three stacks cribbing on each side, remove cribbing as I reached each stack to keep the boat stable.
If you do that, make sure you stack the cribbing more like " # " with at least two blocks per layer, and not just one block on another.
Cribbing was various chunks of 8x8,4x4, and 2x6 Lift it, fill space with thinner cribbing, go to other end lift it twice as high, fill the space replacing thin stuff with thicker stuff as you can.
Whether it's a viable option depends on the cradle. With the triton cradle, it's heavy duty enough that I've actually considered just mounting axles and a tongue on it. (8x8 square tube)