Some parts of the Lake of the Ozarks does freeze some during the winter but not all of the Lake of Ozark freezes.
When it gets really cold out then sometimes part of the lake of the Ozarks will freeze over and the Lake of the Ozarks is also usually drained down or drawn down to protect the health of the water in the lake and kill off any potential bad lake weeds.
The water is also drawn down in the Lake of the Ozarks to help protect the docks and other parts of the lake.
It's very rare that the Lake of the Ozarks freezes over completely although sometimes if it gets severely cold then all of the Lake of the Ozarks may freeze.
I have heard that the Lake of the Ozarks has completely frozen over years ago but like I said it's rare that it does freeze completely.