The hive that was decimated by the cold unfortunately didn't make it, as there were too few bees left for it to pull through. I was wondering why there were still bees in the top boxes in the hive the swarm moved into (No. 6), so I pulled it apart to find out.
I thought I'd shaken all the bees down into the bottom box, below the queen excluder, but there she was at the top. The bees won't desert her! She's marked green (last year's colour), so that was presumably when she was raised. She's quite small, without the distended abdomen I usually see in queens. She's not laying either, so she may still be slimmed down from swarming. I'll have another look in a week or so, and see what's happening then.
Meanwhile I'm still planting tender veg. The germination I've had from my squashes has been vole, and I don't know why. I've had them on a warm windowsill, so they've probably been warmer than in previous years when I had them in the min-greenhouses. Apart from that, everything's come up fine.