I found an easier way to do it.
Simplest way is to go on the EBGames.ca website, find the product code for the Nintendo Switch (from the URL), then go to another product and click the link to check stock in store. Change the URL to match the new product code.
They disabled the link on the Switch product page but you can still check for store stock and it is accurate, this is how I got mine today. They didn't want people to swarm the store every time one became available.
For example, in the Toronto area right now, there are units available at:
WOODBINE CENTRE 500 Rexdale Boulevard
E-COMMERCE ST2499 8995 AIRPORT ROAD
TORONTO EATON CENTRE 220 Yonge Street
CLARKSON CROSSING 960 Southdown Road
ERIN MILLS TOWN CENTRE 5100 Erin Mills Parkway