I can't think of any situation where intentionally abandoning would be better than staying with the boat (except maybe when it's headed for a seawall or large rocks). Your survival odds are exponentially better with the boat than floating in the water.

The boat will give you a place to stay dry(er), and will help rescuers find you.

If the water isn't deep enough to turtle, let it snap the mast, then turtle. If the boat is inverted, and you sit on the windward side, it should stay inverted. Don't sit on the leeward side, or it will come up.

Shouldn't be a tumbleweed unless it's on its side, then all bets are off.

Mike