Thank you all for the responses to my question. Confirms that this forum is full of great folks that are more then willing to offer their help and experience.
We got down to 27 last night so I ran the furnace set on 50. Went out this morning and everything in good shape. Looks like I'll need to repeat the next couple of nights and than we're back into the high 30's and 40's.
Lot of folk's recommended to winterize, but with only having a handful of nights a year that dip this low I felt there would be some alternatives, hence my question on this forum.
Also had one post commenting on leaving the trailer plugged in all the time. I have a Magnum Inverter/Charger that maintains the batteries and doesn't just continually charge. Plus I have it programed to time connect, so it comes on from 12 midnight and disconnects at 4 am.
Again thanks for all the information and suggestions.