Ask Mr. Smarty Plants

Sumacs are a bit of an enigma; they spread like crazy and pop up everywhere you don't want them, yet they are notoriously difficult to transplant.  The challenge is compounded when transplanting at a cottage, as most plants need to be watered every couple of days for a few weeks after they are dug up and moved.

However, that does not mean that you shouldn't try as I have seen my neighbour do it successfully!

You have greatly improved your chances of success by indicating that they are babies and that there are ten of them.  Wait until they are getting ready to go dormant for the winter (starting to change colour) or some time in late September when the air is cool but the soil still warm.  This is important because the compromised root system will not be able to take up enough water to keep the plant alive if the sun is strong and the air very warm.  Transplanting them while the soil is still warm gives them time to generate some new roots before winter dormancy, so you wouldn't want to try it after Thanksgiving.

When you do decide to move them, try to minimize the amount of time they spend out of the ground.  Dig them up just before you head to the cottage, wrap their roots in wet paper towel or rags and place them in plastic bags. Plant them as soon as possible when you arrive and water them.  Keep the soil moist (but not soggy) while you are there. If you are lucky, it will rain during the week while you are back home and some of them will survive.

You might also try digging them up now and getting them established in pots in the shade at your home before moving them.  They may transition more easily to independant life at the cottage that way.  (I would be tempted to do half of them using one method and the rest the other).

Good luck.  If none survive, try again; you will surely have more in your yard in Aylmer before you know it!