Leaving water in skimmer when closing

[DIYLinerPool]

I am using my auto cover as a winter cover so will be leaving water in my skimmer when closing. Is a gizzmo all I need? Or do I need a skimmer faceplate that doesn’t let water in as well? Just wondering if it’s ok to let that “door” that leads into the skimmer frozen in water. Thanks!

 

[wireform]

I'd flatten the door down so it can't com up and fill the skimmer with pool noodles with long enough pieces that start and end in the pool, go in and around the gizmo sort of in a U shape. This way the won't come loose in the winter.