Dog Dilema?

Backstory: I live in the desert. So until I can afford to put grass down my front yard is dirt. I have four dogs. I didn’t intend to have four dogs. I started off with three and then I found out one of my dogs brother was being abused so I rescued him and now I have four. They are getting a bit unruly.

Because I live in the desert when I am at work they hangout out front. I have a good sized yard but because they have access to both inside and outside they bring in A Lot of dirt. A lot. The way my house is set up, I have a very small “garage” I would say a bit bigger than a walk in closet and was used previously as a tool room when my grandpa lived here. Now I just have some chairs in there.

I was thinking about closing the dog door permanently (which is through the garage and I just the garage door open slightly so they can go in and out) and setting up the area for them while I am not at home with water, a dog bed, and possibly a heater. I do work late, until 800PM, so it gets really cold. Does this count as “outside dogs” though? I personally don’t like having outside dogs and want to make sure that since they will still be able to sleep inside that they are just hanging out while I am at work.

I have a husky, two Belgian Malinios / husky mix, and a border collie / Aussie mix. I think the first three will be ok with the cold but not sure about the Aussie. I feel bad for not letting them in when they want but there is just so much dirt.