I don't think you're over-zealous Kate. We often have winters where there is only one or two cold nights in total. In fact last winter was that way. Pretty sure I only pulled the orchids in twice and both times were in January.
This year? Who knows what we're in for.
One thing that is for sure though, your orchids may survive being exposed to cold nights, but they will do much better if you protect them when the temps drop below about 55deg. Phals do ok in cooler temps but the others just sit and pout for months like the tropical divas they really are.