it would depend on how bad a winter we get. if the pots can be placed somewhere sheltered then they should be ok.

The idea is to not let the soil freeze solid.

would it be a good idea to just bring them indoors anyway?

I think they would be better in the ground,Kate,if possible.
I put some in pots,but lost them last year,but the ones in the garden were fine..

As Bloomer has said, put them in the ground. They will be more protected from frost and Alliums do not do well in pots at all.

Damn they are already in pots..can I carefully take them out and move them into the ground or not now?

Fine to move them this time of year. They will flower in a pot but will be smaller, thinner and will not last long. In the ground is by far the best for them, especially over winter.