Tough call. I have overwintered geraniums for 3 years and set them outside in a whiskey barrel that is now way too waterlogged and heavy to think about moving.

It has rained for 2 days straight and it looks like at least another full day of rain today and tomorrow. The temps last night got down to 35 and we had sleet.

The geraniums appear to have made it through OK. Who knows though with this weather how long anything will last.

I'm in the same boat. We had wind-chills of 30 degrees today and 40mph winds and steady rain yesterday. Rain is forcasted for the next ten days. My annuals are in flats on a covered porch that is fairly sheltered. So far so good. I have one caladium that has moved indoors with me. Since the others are already hardened off, I think they will be ok. If the mothers' day pots are not too heavy, you could put them in the garage at night. Ask the greenhouse if there are any really tender plants in the pots.