I believe maples need to experience the seasons to be healthy. They won't survive indoors. What zone are you in? Once this freezing passes, can you bury the pots in the soil outdoors and give them a good mulch (not touching the trunk, but covering the soil)?

I had the same question but my maples are larger, in 16 inch pots. Just planted this year. They are on my deck, so I thought about either garaging them or at least keeping them under the portico. I lost a large maple last year due to the freeze.

Ant extra advice would be much appreciated.

Pots are tricky.

Try to put them outside someplace the sun will not cook the pots during the day just so they can freeze solid at night. I hide my potted trees in a sheltered area under a dogwood.

GENERALLY I assume a potted tree has a one zone colder experience in the winter than one in the ground.