Heating while away

[MaxwellD]

I have been deliberating on whether to leave the furnace on a low setting (50 degrees) versus a higher setting 65-70 degrees while the rig is parked and plugged in unoccupied for a time. Obviously it doesn't need to be at 65 degrees and the logical choice is a lower setting. But the question is: will a furnace cycle more to maintain a higher temp or cycle more if the lower temp is set? To me, it would seem that colder, denser air would be more stable and the unit should cycle less to keep it at 50 degrees instead of 65. But I don't know. All I do know is that my 3730 FL is a propane hog either way. Can someone shed some light on this question? All of this assumes no effect from insulation - maybe that is not a safe assumption?
Thanks in advance.
Max