My dragon trees were left in the greenhouse (this is Britain) overnight a few weeks ago and here was a very hard frost unexpectedly. I came out in the morning, worried, and my dragon trees (as well as some jade plants which have been dealt with and are fine now) were all wilted and looked dead,many only the day before they were looking healthy, with their levels upright, and now the leaves have turned dark green, are droopy and are very slowly beginning to turn brown.

The trunk, however, seems to be fine.

Should I cut all the leaves off or should I prune the top of the stem off so that new stems can form?

Thanks.