I have been asking myself the same question.
I started with 4 plants this year and they are spreading well.
However, as they are in an old bathtub in the yard, I cannot move them inside.
I'm thinking of covering with straw?
Last fall I covered my mint with leaves and everything came up gangbusters this spring.

Strawberries - when planted in the ground - just need to be covered. straw is a good idea. I would put them somewhere in a shady spot outside instead of sunny to avoid too much warming and thawing and cover them up. The heated garage might end up being too warm and they still need moisture to live.

In the shed then? What should I cover them with (please don't say straw...) and should I prune the plants as well. I'm a newbie at growing strawberries as you may notice....

I live in southern Alberta, I have a strawberry patch in the ground and a strawberry patch in cinder blocks, as long as they are in about 6-8" of soil you can just leave them and they will come back next year, they will dry up and lose their leaves perhaps but should be fine, as you only have a few in planters I would risk it, just leave them be...somehow strawberries lived through winter before people were around to |protect them"...lol

Even in the dead of winter plants in the ground get some warmth from the ground, especially if the snow is deep. Things in planters need to have the roots sheltered.
I think the plants in the bathtub are at the greatest risk.
Heap snow around that bathtub planter, dump a foot or more of leaves on top of the plants. If you move planters in to a building put plenty of moist leaves or straw to keep some moisture there.
You could just place the railing planters on the ground and bury them under all the leaves you collect.

You could just place the railing planters on the ground and bury them under all the leaves you collect.

I think I'll try that...

Agree, just put them to the side and cover them well with the fall leaves, and they should be just fine

Please post pics of your plants