The pandemic probably spurred frivolous online spending, but back to reality and inflation, some people will be tightening their belts again. As much as I love pretzels, I'm too cheap to buy them at an ultra premium for what is just flour, water and salt. I think this will be especially true for the single item orders (with a drop in indulgent covid spending). But I'm guessing the .COM guys are seeing an opportunity - I don't have specific evidence but my guess is that Canadian shipping costs are much more expensive than U.S.
That being said, since you're making it work with candy I suppose it could work with pretzels. The one thing might be that pretzels are more delicate and shorter shelf life than a lot of candy. I grew up eating pretzel rods and they're difficult to find here. I buy stuff occasionally from the Bulk Barn locally, and their pretzel rods are always broken to bits and stale. Shipping them could result in breakage too, especially for the long rods.
However, I'm always shocked at how some people continually spend frivolously, so it will be interesting to see what trends you actually see happen as life gets back to normal.
Weddings, kids birthdays, and corporate gifts, etc... Those tend to have more indulgent buyers, both tend to come in bulk orders, can tolerate a higher customer acquisition cost, as well as reducing shipping cost/unit thus maintaining a decent profitability. My gut just says that would be your bread and butter. Not sure how many would order just pretzels. Having pretzels as part of the candycrave lineup might make more sense as an add-on than as a pretzels-only order. If you could have a universal shopping cart and let people bounce between your niche stores and ship all in one shipment, that would fix those narrow niche issues as well as encourage additional sales.
I'm sure you're getting really interesting data to see these real world sales first hand and can hopefully see some trends happening. Much to be learned from that data!