Frozen tip ups

Looking for advice on frozen tip ups.

Went fishing the other day, and all of our tip ups froze up in 0 degrees f, making us miss at least a dozen walleye.

The tip ups vary from old beaver dams to newer cheap HT ones. They’re spooled with standard tip up line, and it seemed like the line itself was frozen into itself, and wouldn’t roll off the spool.

Any advice here? Different line? Different tip ups? Grease existing tip ups? Or do they not work at these colder temps?