Use old flowerpots, doesn't matter what the container is. If you don't have any, then cardboard boxes will do, but you need to line them with plastic first. Best kept over winter in sand and peat, or sand and multi purpose compost mixed, even spent compost that you've used this year mixed with sand.

Thanks Bamboo, will the spent compost from a grow bag I grew cucumbers in be ok to use?

Probably, but you really should mix it half and half with sand.

Let the tubers dry off first and knock off as much soil as possible.