Ice can destroy filters, housings, membranes, pumps, connectors, heaters,.. even the spindle on your reel can split from freezing. It could be an expensive mistake to let it all freeze,...
Definitely don't let it freeze, can cause all sorts of problems.also (something I didn't realise) is its not good for the RO membrane to dry out, as in left more than week or two.....
last Jan I went new Zealand for 5 weeks, drained and dismantled system and stored in house. only after did I find out can damage filters this way. I got lucky, seemed to work just as good (nearly).apparently should be filled with water, and the waste valve closed to keep water in...... so it's kept wet. just make sure not gonna freeze!I'm sure a lot didn't know this, I'm sure you'd get away with it.....but just so u know.