@Miamiu Eric, I think if you give the plants a nice bit of water right before you stole them away, they'll be fine for four days. I'ts supposed to rain here the two days before the front, so nature may take care of that for ya.
I'm watching, it always seems to go a bit lower than what they predict at my house, so 40F could be upper 30's. The duration of three to four nights stinks.
I don't have much to be concerned about if we stay above 40. That said my pop up greenhouse is still up and waiting just in case.