It freezes fine, IMHO. In fact, I think its actually better in one way after its thawed -- as with most vegetables, freezing ruptures cell walls, allowing liquid to seep out upon thawing. I like to put the thawed squash in a sieve and let it drain for a while, because one thing I don't like is soggy sauce that can result when salt leaches water from the cooked squash -- this eliminates that problem.

I often freeze mine when they start to go bad -- s.s. isn't the best keeper, so this solves that issue, too.