They should be good for several months. Cool, dark, dry is the key. Think of those old root cellars.

I'd be tempted to lift them so that they dry off then store in a cool dark area. Probably at least a month or so I'd have thought. They may get nibbled by slugs or any other soil pest left in the containers especially if damp.

I leave mine in the tubs, they seem to keep fine but if I don't pick them before the spring they start growing again.

Thanks all of you! Take your point, Seaburngirl. If I was keeping them outside, I might well lift them. However, as they are already in the greenhouse I will leave them a little longer as required.

Season's Greetings to you All!

I was just wondering if there were any slugs in there from when they were growing outside. Many of the ornamental pots that I bring in often harbour them.

I haven't detected any but I will take a better look tomorrow. A good job for Christmas Day! Thanks for the tip. I regularly check the taters when they are still growing. I have never had the problem with containers but something chomped their way through my main crop last year when I planted them out! That's why I tend to favour container growing. Thanks again, Seaburngirl. Your expertise is always valued.

Joan, just a thought - I sometimes add a small amount of slug pellets in the hole when I plant them and rarely have much trouble but keeping fingers crossed...
This link might be useful
https://www.growveg.co.uk/guides/how-to-prevent-slug-eaten-potatoes/

Thanks for this tip, Yorkslass. I will bear this in mind with my next tubers. Thanks also for the link.