Yes I have a 3/8” line. I did have that suspicion as well when it would happen late at night/ early morning when it just started getting cold and obviously the temp would be the coldest at that moment.. is there a pre moisture filter catch I can throw on if that’s a thing? To prevent the build up to begin with? Or is that iso drip / replacing the line my only option?

It’s running right now sub 32f. Don’t know what the humidity is but I do think what y’all are concurring is my fear.. I probably won’t replace the line until spring