A week of gradual exposure, or one cold night takes everything
The schedule
Two hours out on day one, doubling each day for a week, in shade first. Back in every night until the last two days.
What kills them
Wind more often than cold. Soft indoor growth desiccates in a breeze before the temperature has done anything at all.
The shortcut
A cold frame does the whole thing with a lid you prop further open each day. It is worth building for this reason alone.
