Sorry but I can't give you advice about any dealers on Vancouver Island. My best advice:
1. ID all the dealers in that area, if you're focused on "buying locally";
2. Contact each one; find out how many allocations they've been getting for the 2021 and 2022 years. That should give you some idea what they might expect in future years however their Stingray numbers will diminish for the Z06 version (as mentioned by dyoung) and likely even more for the other versions when they come out (the E-Ray, ZR1 and Zora...not so much the Zora which should be ++ rare);
3. Find out where you'd be on their C8 Stingray list;
4. The dealer who gets the most allocations and has you the lowest on its list, would be the one to go with. That assumes they religiously honour their list...and don't (for example) take allocations for the dealership or friends/family of the dealership owners (I'd ask what they've done historically);
5. Don't be shy: get on at least one other list to improve your chances;
6. Another factor: see if the dealer will confirm they'll sell you a C8 at no more than MSRP and get that in writing (assuming you're not willing to pay over MSRP). Beware paying over MSRP and still waiting ++ time; other dealers might sell you a C8 at more than MSRP with a reduced wait time. Some of the dealerships in my area that are Wheaton family owned, are asking for more than MSRP. The one in Red Deer wasn't ordering any for customers; they took all allocations for the dealership and then sold each at well over MSRP;
7. I wouldn't focus on who has a good service department. Your warranty will be honoured at any Chev dealership. Focus on getting your C8 first since it's hard to get; worry about where to service it AFTER you'r driving it. Factors to consider for servicing: does the dealer have an experienced Corvette (C8) tech? Dealers who get more C8 allocations usually do;
8. If the C8 Stingray list is too long, consider getting your name on the list for the E-Ray, if that's a vehicle you'd be interested in. Or get on the E-Ray list and remove your name, if you decide later when more details come out, that it's not for you or you get a Stingray sooner;
9. Finally, if the dealers on Vancouver Island don't get many allocations due to the population base they serve, I'd seriously consider getting on a list elsewhere with a dealer that gets more allocations (again; consider getting on multiple lists), assuming you'd be low enough on a list to get an allocation faster. I've purchased and shipped cars across Canada several times and don't mind shipping if it gets the car I want, faster. There are many reliable vehicle shippers and I've never had a problem. And I've known some on these Forums to buy in Edmonton and drive their C8 home to BC. Up to you of course since this adds to your cost but you're looking to get a car that's in demand and if you're like most of us, you'll LOVE driving a C8 and regret the wait if you could have had one sooner.
The more "homework you do", the more your effort will pay off and get you behind a C8 sooner. Good luck!