I feel your pain.
Our house had been empty for several years before we bought it. We didn't just have mice, we were the community condo for them. Occasionally suffering from insomnia I would hear them at night partying in the walls. Hubby didn't believe me until one came out in broad daylight to go after cornbread that had just come out of the oven.
In the first week we trapped almost 100 of them.
Now, every October (when they start moving in) we put d-con in the attic and the cellar. Mice don't die from eating the d-con. They die when the d-con makes them so thirsty that they must find water. d-con plus water is toxic. They will go to the closest water souce.
I have 3 children, 1 dog, 2 cats and 9 chickens and haven't lost any of them to d-con.
good luck