Broad beans in pots - what to do next?

I missed the boat on autumn sown broad beans so stuck them (Aquadulce) in pots early this month. I didn't factor on sudden snow/permafrost in London, and they are coming up now.

I can't put them in the plot, which is still covered in snow, and I live in a flat - are they best off:
a) in the brightish but north-facing unheated kitchen?
b) on the cold landing by the balcony - also north-facing and near the builders who are putting a new lift into our block?
c) on the (1) sunny windowsill in the flat in a warm bedroom?

Thanks - I'm having a small brain freeze!

thanks DD, much appreciated!

If got a similar situation to surbie100.
I've got loads of broad beans that have germinated and I had wanted to put them in the plot but the recent snow has put paid to that for a while. Will it be too cold to put them in an unheated greenhouse? I can do this is in stages moving them to a cool, east facing room before going to the greenhouse. They are currently on a windowsill in a study that has no heating within it, but draws warmth from the hallway /rest of the house that it opens onto. With the obligatory foil of course 

Just done a broad bean inspection (autumn sown).
The ones outside have survived quite well, but are small compared to the ones I sowed in pots in the unheated GH. These are now producing their first flowers!!!

Mine really need something doing with them, and quickly. Trouble is, I'm averse to put them out and get them whacked by a frost. The way the weather is perfoming, I might manage to get them out about June/July!

You can still do it 
After the cold snap they'll soon carch up.