I currently have only five heuchera, but that's because I'm so picky about the foilage colors and can't always find what I want. But now that I've decided I want this plant and lots of it I'll be collecting a lot more. So from my info above you know I don't have wintering problems.
I'm a container gardener for everything. I have some of these in clay pots and another in some fancy concrete + something bowls. They've all come through the winters, and for us 60* is too cold, so getting down close to 32* is a worrisome thing.
The amount of rain we got this year was very close to being scary, but the heuchs are all under eaves or roof edges and they got enuf rain, and they have excellent drainage, of course, and I make sure of that by checking for obstructions in the drain holes once in awhile - yeah I get fussy about some things - the dogs are at least polite enough to wait for me to leave the room before they kick off the covers I put over them. Obviously if my feet are cold, the dogs have to be covered up.