That’s real frost not bud rot looks beautiful actually!
One night of frost won’t kill her, but if temps keep dropping below 0 °C, moisture can stay trapped in the buds and then you risk bud rot.
If the forecast shows more cold and humidity, I’d start the flush and harvest within a few days.
Otherwise, you can let her go a bit longer just make sure she dries out fully every morning.
Amazing colors by the way