French beans

Hi all, as an avid collector of seeds, (some times with suprising results) I'm not sure what to do with my french beans, You see I planted them late and now i find the pods are full and but still green, the problem is do I collect them now or leave them with the risk of them getting frosted?

 

I would collect a few and leave a few.

 

Firstly, according to www.theweatheroutlook.com ,minimum temperature forecast for Canterbury is 5deg C next 16 days, so no frost! I am in the same position so have fingers crossed.
Can you be prepared to cover sufficiently overnight if they prove wrong (are they ever?)
Secondly, do they have a value beyond the case of replacement ?
If they get to go towards ripe, you could chance pulling some plants and hang to dry in a airy space(shed/garage). They then probably would be viable, if you can stop them rotting. When poddable, dry off as usual and store correctly. Best to test germination early next Spring before its too late to replace.