Google citrus groves and find out what people do to keep the oranges from freezing.
They tent and spray with water i think.
Anyway im from minnesota and have had some tough bouts with frost myself.
The buds can take a frost as low as 29 degrees without much damage, any lower than that you need to cover her with a tarp of some kind.
Usually the first cold snap only lasts a couple of days, then a couple more weeks of good weather. If you can get to her easy enough to cover her for a couple of days, It would be preferable to cutting early.