I had a buddy with a track hoe help me pull my engine. He couldn't bring it to me, so I towed my boat to his place. He picked the engine and set it on a tire. I towed the boat home, dropped it off, picked up a utility trailer, and went back for the engine. When I got home with the engine I was able to pick it off the small trailer with my engine hoist. It was a lot of driving, but if you know someone with a similar piece of equipment close by, it could be another option to consider.
Hoestly, if it were me though, I'd probably be using that oak tree and chain fall you mentioned. You can hook up the chain fall and start to lift, and evaluate how the tree appears to be doing as you load it up. If you can get the engine fully supported on the chain/tree and things look good, pull it the rest of the way out, move the boat, and lower it down to a stand.
Hoestly, if it were me though, I'd probably be using that oak tree and chain fall you mentioned. You can hook up the chain fall and start to lift, and evaluate how the tree appears to be doing as you load it up. If you can get the engine fully supported on the chain/tree and things look good, pull it the rest of the way out, move the boat, and lower it down to a stand.