Resurrecting from Torpor seems to be a horrible pain on purpose because of that.
What I've found is that vampires succumbing to the Beast will prioritize blood packs instead of living colonists if they can reach them.
So hopefully you have Dominate or Psychic Shock Lances laying around for you to extract some blood from your colonists/animals in time while you lock them in a plasteel room or something.

That's why I'm much more careful about letting them die even if they can resurrect, you can also leave them torporious forever as long as they're not in sunlight then extract blood to prepare to resurrect your fallen cainite.