You may not even need the wood.
You can put a piece of plywood on the ground to protect the skeg and driveway from damage remove the top bolts, loosen the bottom ones and crank the front up as you said.
It works very well.
I recently replaced the bunks on my trailer using the same technique.
Crank the tongue as low as it will go, put axel stands with wood blocks under the rear corners of the boat, crank the front as high as it will go, block up under the bow and lower the tongue a few inches to take the weight off the trailer.
Now your traile and boat are separated by a few inches. Enough space to get under and work on the trailer bunks. Sure beats trying to do it in the parking lot at the ramp.