You might check with your vet about the CRF, but I've had good luck with Feliway.

Put it in your cat's room, & put it in the other cats' territory as well to keep them from clawing at your cat's door.

When one of my kitties is under stress, I sleep in a different tee shirt every night & put last night's tee in the cat's bed, so he always has a fresh sample of "eau de sylvia" to snuggle into.

Be sure his room is warm, & give him some comfortable hiding places;
if he wants to hide under the bed, as we all sometimes do, be sure there's a comfy shallow box with some tee shirts in it.

I hope all goes well.

Before our last move (we moved from AK to CO in winter and took over a week to drive), we got a small soft-sided (fabric sides so it was darker than others) dog kennel for the two cats a few weeks before we left. We introduced it first in our living room(and fed them lots of treats inside it) so it was a familiar and positive place . They were confined to the kennel in the car and had it for a "safe zone" in the hotels.

When we got to Colorado, we stayed with friends for about a month. We each had 2 cats and 2 large dogs, so it was a house full. Our cats were confined to our room downstairs and their cats were confined to another area of the house. We kept the cat kennel in the room for a few weeks, until they were more used to the new place. When we moved into our own house, we gave the kennel again for a while. My older (and more neurotic cat) really seemed to use the kennel a lot. He felt safe and relaxed in there.

Thanks much for the info. I'll be keeping all things in mind!

dwmc, what sylvia and greenbean said were both great advice. Bear in mind that cats are way more territorial than dogs.

In fact, cats will chose a territory based upon time of day in a home. Example: A particular dining room chair might be one cat's territory from 11 am to 5 pm, and another cat's after that time at night.

I think you're wise to confine your cat to a particular room for a period of time, and excluding the other cats from it during that time. You might leave a screened way for the other cats to stroll by (think "baby gate" or some such) so that they get to know your cat through the gate without anyone getting threatened.

In a shelter, we successfully house multiple incoming cats all the time. Generally we house 3 small dogs in a kennel together, or two large ones (metal kennels). However cats are different. Many shelters have 3 "Cat Rooms" -- one for neutered/spayed cats (both sexes) -- one for all Males -- one for Females. Many cats can stay in those rooms (think Bedroom size), housing up to 15 cats (maybe 20) each quite successfully and peacefully. Many of those cats have never met before either.

However, we always observed certain cats claim territory over certain areas but only at certain times of the day, then swap off.