In Java 1.16.1 you can go through the doors with a boat, the only thing you have to do is stand against the door, or a wall, and place a boat directly beneath you, facing away from the wall, after a few tries you can go backwards with your boat and go through the doors/wall, or whatever block is there (I've tried with a variety of blocks and they all seem to work, you only lost about 3 hearts going through there with your boat, even bedrock works).

I asked a few friends to try it, they all did it and it worked, I've tested it in survival and creative, and there doesn't seem to be a difference other than suffocating in survival while you're going through.