Yes, the polar vortex did a lot of roses in this year. So don't feel bad about losing yours. Sometimes things just happen.

As for bringing them inside the house I do NOT recommend it. They will not be happy and you stand just as great a chance of losing them inside as you do outside in the garage. They won't get enough light and the humidity will not be right for them. They just fail to thrive inside. Put them in a protected spot in the garage, where they won't get blasted every time you open the door, up off the floor on blocks and water them some every month through the winter. It's still the best chance they have of making it. We can't predict the weather but hopefully it won't be as bad as last years.

Roses in the house will be ruined by spider mites unless you fight them constantly. Even so, the plants will be unhappy.

Another way to winter potted roses in zone 6 is to push them against the south or east foundation and pile leaves around the pot. When very cold temperatures impend, add some more leaves over the pot, but expose the canes during mild spells so they don't stay wet.

I put layers of blankets or sleeping bags on my roses. Then in the spring, I start to unlayer them.
Hope you have better luck.
Carol