Don't forget, the unit, especially if it's a four season unit, will be a lot warmer inside than the ambient outside temperature because of daytime heating.
12 plus hours of 30 deg above freezing (daytime) will create a lot more heat than 5 or 6 hours of near freezing will cold. On top of that the contents, right down to cabinets and furniture will absorb that heat and slowly release it back into the interior as temps drop.
I think you'll be fine.
As a future tip though, if you have to leave it in cooler weather like that again, be sure to leave all the cabinet doors open, it allows the heat to easier penetrate the interior spaces nearest the plumbing.
