I get geranium and poinsettia cuttings shipped from Mexico and central America by air. They are packed in a box with frozen ice packs. You might want to cut the geraniums a few days ahead and keep them in a cool place away from the sun. They will heal around the cut stem and become stable for a long time. I have often found broken off stems of geraniums on the greenhouse floor that fell there and looked good a week later... Bob.

sunnfarm3 you are right about the cuttings. In fact I take all my cuttings and leave them exposed to the air on my spare room floor for 5 days before I plant them, with rooting hormone right into the soil. Letting them callus over greatly reduces the incidence of blackleg. They look like they are dying for about a week and then slowly start to grow.

I like the idea of ice packs to keep them cool, but I'd be careful that the ice packs don't touch the plants. A layer of newspaper between should work