Things that will make your cat happy in the winter:
Play with them, I personally recommend the DA Bird interactive feather toy
Teach them a trick or two, my cats know how to sit and my Maine coon sits pretty and my orange and white cat sunshine comes on command, don't ever under estimate how smart a cat can be.
Scatter their toys on the floor and they will be more likely to play
if you only feed your cat once or twice a day you could put a trail of cat food on the floor and up high were you know your cat goes to make it like a treasure hunt
also if your cat likes cat nip you should get them some fat cat toys and a fat cat boogie mat
For the Dogs:
play with them inside
if they like the snow come up with games like burying a treat or favorite toy under a pile of snow and having them dig to find it
practice their tricks they already know or teach them some
scatter treats around the room while they are in another and them have them find them with their nose
play a game of hide and seek
get them so good chew treats like greenies, zukes z-ridge, bright bites, and blue chews.Lamb ears, Cow ears what ever your dog enjoys
stuff a Kong with peanut butter
No matter if you have a fat lazy cat , a huge dog that loves the snow, or a small dog that gets cold very easily and hates to go outside, just use your imagination and you are sure to find endless ways to keep your pets minds busy and out of trouble and make them very happy.
One of my jack a bea's favorite things to do is go to the petstore and walk around not to mention the car rides to the post office or thru the drive thru.