I'd have thought there'd be a good enough way of getting a seal on the freezer if you thought hard enough about it. And with regards to the water freezing, I'd have thought it would be able to heat the water up above freezing, plus if that was the case you're actually in a good position because you could adjust the temperature of the freezer to find a sweet spot where the water is cold but not freezing.
I'm aware that i'm defending a bit of a stupid idea, but I thought I'd still try to counter your points
And yeah like a condensing tube you might find in a lab, just run tap water through a glass tube with 2 compartments haha.