Dwarf French Beans

I'm growing some dwarf yellow wax beans, I started them off in the greenhouse but they are really getting a bit too big for the seed tray they are in. Do you think I could risk putting them out yet or should I transplant them into something bigger - it would be a bit of a job as there are quite a few. I'd sort of been trying to hold off for a couple of weeks yet but I'm wondering if I could risk it?

Exactly what I'd suggest as beans really don't like being in pots or tiny modules. They can take a certain amount of cold but fleece will keep any frost off.