Outdoor cats for a farm setting

[Betty]

We are moving very soon an area MUCH more rural then our current area. It's a cute little house on 2 acres with another house fairly close on one side and some buffalo in a field across the dirt road. A few goats down the way... you get the idea.

We also have a barn which clearly has mice. I opened the door - saw a mouse or two and closed the door.

I can't have an indoor cat for several reasons I won't go into.

I'm wondering though - how about a few outdoor kitties that will help to keep the mouse population in control?

My grandparents had a ranch I'd visit summers growing up and they always had some barn cats lounging around.

We have some feral cats near my office that sometimes get into the factory area, get closed in at night and end up setting off alarms. (They caught one in a wire trap this morning that holds her in the little box without hurting her.) There is a whole family on the other side of the chain link fence and they aren't kittens anymore - but not quite adults either.

What are your thoughts on outdoor kitties in a rural setting?

Wouldn't it be better to have them out on our little property then getting trapped and taken to the pound and probably put to sleep?

What should I know about having outdoor kitties in that setting? I would like to provide them with a nice warm shelter of course that's suitable for outdoor temperatures.