I think Nintendo learned their lesson from the disastrous handling of the NES Classic Edition situation. They got a ton of bad press and angered a lot of people by failing to provide enough units and encouraging scalpers. The SNES Classic Edition has been much, much easier to find, I already have two of them, one from Target and one from GS. In fact I could drive over to my nearest Target today, and get another one if I wanted to.
Istocknow has been a great way to locate these when they hit stores; Target today shows 761 stores in stock including several around me in Northern VA. They only show 283 GS stores now (none around me), but I've seen it hit 1500+ for both of those retailers, which happens when a big restock hits. When those numbers jump up to 1000-1500+ stores in stock per retailer, they are typically easy to find. Oddly Walmart isn't even listed on istocknow today, so they appear to have no units (unless they are masking quantities from this website).
Retailers have learned a good lesson too; many have made it much harder to track units through their own websites, discouraging scalpers, and keeping units off the floor. The second one I got, I just went to my local Target (which showed in stock according to istocknow), and asked for a unit at the electronics register. The guy went to a back room and brought one out, they're not putting these on shelves (another good idea that helps prevent scalping). I do think that anyone who really wants a few of these should easily be able to get them.