Setting the date

I actually just realized you're talking about 2021. I thought you meant 2022 for some reason. I take back my advice in this particular situation for reasons that have nothing to do with your bridesmaid. Even if we do get a vaccine in the first half of next year it's possible there will still be restrictions going into the summer or later. I’d push it back to the later date or even later if possible since the July date has no particular meaning to you and your partner. It’s only a month between the dates you mentioned and so it might not make a difference, but it would suck to have to have restrictions if you could’ve waited a month longer and had a more “normal” wedding.

It's also worth noting that BC has stricter covid restrictions than AB. In most of the province you can only have 6 people attend a private residence in addition to the occupants - in other parts you aren't supposed to have any gatherings right now but the island is exempt from this. It's possible that the 6 person rule might still be in effect next summer depending how things with covid go. However if you have your wedding at a staffed venue then you have a limit of 50 people.

Considering July holds no specific significance and your only gripe is having to wait an extra month, I would go with August just so you can include your bridesmaid who I presume was asked to be in the role and accepted because she's close to you.

You know what would work best for you to make the best judgement call to have the one bridesmaid present on your original date or to wait until a month later to really want her by your side. This is something that matters to you dearly knowing she is one close to you.

This is a hard choice on you and I hope the day is still special in which you choose.

I personally wouldn't change your date for just one person. Unless you can't see yourself without that one person being there for your big day.

I personally wouldn't choose/change a date for a specific person unless it was a person that is an absolute must attend like a parent or best friend or whatever that person might be in your situation. It's also possible that something happens after you've scheduled everything and someone important can't make it. For example, a few months after we set our date we found out my sister in law was pregnant and due basically on our wedding date. Even though we knew that my brother and SIL couldn't make it (they live out of the country and would have to fly) we weren't about to change all of our plans to accommodate that.

Basically what I'm trying to say is it's highly unlikely that everyone you want there is going to be able to make it so I don't think it's worth stressing about finding a date that works for everyone. Something else to keep in mind is that next year is probably going to very, very busy for weddings so chances are no matter what date you choose some people will have conflicting plans.