Removing smell of previous cats and avoiding spraying

My SO and I have one cat and are house-hunting. We've seen one house
that we like very much, but the present owner of the prospective house
has 4 cats.

I'm worried that our cat (an 11 year old spayed female, who does NOT
like other cats) will react to the move and the smell of other cats
by spraying everything in sight.

What can we do to keep this from even starting? Several of the rooms
have brand-new carpeting.

Marli

If you buy this house, I'd come early in the day to scrub out the
bathroom (including the walls). Move your cat's litterbox and etc.
into there, and make that her temporary home. Plug in a Feliway
diffuser to help calm her, and you can put a few drops of Rescue
Remedy in her water too. Bring a towel or blanket with your smell on
it for her bed. When you're moving in, keep the door closed! You might
even put a sign on the door saying "cat inside, do not disturb." so
she doesn't run out.

If you really feel she will have a hard time with other smells, you
can steam clean the carpets and wash (or paint?) all of the walls
ahead of time. Plug in Feliway diffusers around the house. S-l-o-w-l-y
let her have access to other parts of the house, as she feels
comfortable.