Yeah, it doesn’t look like your extension could be approved in time for you to file for AOS. IF it is approved. You used not wanting to travel in the pandemic as an excuse, but apart from mom’s salient observation about it being easy enough to get back to Canada for a Canadian citizen, the timing means you must have traveled into the US in the pandemic in the first place. Not sure how uscis will regard the reasoning.
There has been a huge backlog for both biometric appointments and processing for i539, by the way. Many people have only got bio appointments very late in the process, in some instances even after the requested extension period had expired. Average i539 processing time this fiscal year so far has been 9.6 months.