I have fished here in Alaska for 25 years. I've used Orvis, from Battenkills to CFO's, ULA, Hardy, Saracione, and an old Cortland and I've never had one freeze up, not even late in the fall or winter when it's below zero. I don't know that I've ever dunked one though. I would think that the light coating of oil would help keep it from seizing up. For frozen guides I use Pam oil spray. Hasn't hurt the fly line over the years and it helps to keep the ice from sticking to the guides. Just my 2 cents worth.