I think your main concerns are adequate drainage and possible heaving due to freezing and thawing. I don't grow my heuchs in pots, but I do grow quite a few hosta in pots.

Make sure your pot has enough holes for good drainage. You may want to drill a few more (if it's a plastic or foam pot), You could also tip the pot on its side if you're worried about it. Tipping the pot on its side will keep your plant from getting soaked if you get heavy rains.

Terra cotta and ceramic pots tend to not be able to handle the winter very well. Many times they'll crack and leave the plant's roost exposed to the freezing temperatures. If your pot is of the breakable type, I would suggest putting it under the eaves of your house or pulling it into the garage if at all possible. If not, you can wrap tree boughs around the pot for added insulation.

I overwinter my hosta pots underneath the covered area of my porch or in an unheated garage. I water very sparingly during the winter time; keeping the soild barely moist. Hostas and heuchs hate to have wet feet...they tend to rot if they do.

Hope I've helped. Good luck!

I over-winter hosta and sedum in the garage in pots, but havn't had success with heuchera. It's just too cold here. My good friend replants hers back into her garden, along with other pennials that she digs and repots every summer. Thats what I am doing this year, putting my coral bells into the ground.