We’ve had to board a few cats when we went to FL to see Dad before he passed. I know they were unhappy while caged up but they were fine and normal once they came home. Your two should be fine as well.
The bigger concern is the outside crew freaking out over a stranger. Hope they don’t run off.
We should get a little rain tonight. No lightning showing up on the lightning map in the area where the rain that’s coming here is. A good sign!
They might freak out for the moment, but I’ll bet the food will lure them back. LOL!