Don't count on it
First, pumping out the water is way more tedious than you might imagine. Second, you are betting entirely on the hull seal being completely watertight. Pretty sure mine isn't, which might explain why I didn't seem to get anywhere when I tried to pump out. Boat got to stay in Lake Thunderbird (south of OKC) last year because when I went to pull it, the lake was so low none of the ramps reached the water anymore (and apparently hadn't for months). I put a funnel in the ballast vent, and poured water softener salt into the ballast to drop the freezing point. The lake skinned over for a couple of days in January, but no problem with the ballast. I wouldn't assume, however, that my lack of disaster had anything to do with anything I did, so I am pulling the boat in the next week or two. Grand Lake is further north and will generally be 5-10 degrees colder than south of OKC.