NCIX.com (yes it has physical locations) and Tigerdirect.com (Also has physical locations) they just aren't national chains.
Where I live, BestBuy is right across from a mall from Futureshop (which is owned by BestBuy) , NCIX is one block from the mall. London Drugs also sells Televisions (it's actually more known for electronics than anything else.) Superstore (grocery store) sells televisions. Other parts of Canada have Canadian Tire and Walmart. If BestBuy were to close all it's locations, the slack would be picked up by London Drugs here.
I'm certain in most of the US, there are Walmarts and Costco's that sell televisions as well. At worst, you won't be able to get all the specialty 600% markup monster cables anymore. You'll have to buy all those online.
In small towns, however the national chains don't exist. The prices for electronics, games and appliances can be three times the cost, you may as well buy online. Oh but small towns down't have UPS/FedEX depots.
In my opinion BestBuy's been swirling the toilet ever since they bought Futureshop and started expanding in Canada. Futureshop here is known for pushy sales staff on commissions, scammy mail in rebates and the only way Bestbuy could differentiate itself from Futureshop was saying they don't have commissioned sales staff. Still doesn't get rid of the pushy extended warranty or mail in rebate garbage.
in the USA walmart is everywhere. i'm an hour north of denver for a few more days and there are big box chains everywhere. and amazon will deliver next day if want it to