There's a guy nearby here, in a neighboring town (Endicott NY), who has a tree with about 3" diameter trunk, who does something very much like this. The guy's name is Gianni (Giovanni), he's quite old and doesn't speak much English. His tree is planted so that the trunk is at about a 45 degree angle with the ground (when it's "up" in the summer). The tree is about 6 or 8 feet high at the highest point (trunk+branches are longer than that... they're at a 45 degree angle so that'd be what, something like 8 - 11 feet long). What he does to bend it down is very gradual: he wraps the top in rope and hangs a couple of cinder blocks off of it (attached by rope around the branches), which very gradually pulls it down. He told me every few days he goes out and adjusts the ropes, which he has set to the cinder blocks will bottom out without a whole lot of movement. The whole process of bending it down takes 4 - 6 weeks. Then once low enough, he piles on insulation and tarps, and weights those down too. He's done his winter protection for many years. I have no idea what variety it is, but it's a single trunk at the base, not a bush form. It seems like a lot of work to me, having to adjust the rope length every few days.
Mike central NY state, zone 5