I'm having significant packet loss and ping spike issues for the past 2-3 months in the DY9 area. Only being able to play from around 2am - 8am before increased traffic times. We had a similar problem in 2017 and the cause was too much usage in the area so it had to be increased.
We've tried everything, different routers/modems, upgraded to Gig1 and had a technician around and we are still experiencing issues.
Here is a BQM chart for reference, it's been similar to this the past 2 months.
You could well be correct that this is over-subscription, but the three severe packet loss episodes at midnight, 2:30am, and 4:00am, plus the absence of a "waking up" peak between 6am and 9am make me wonder if there's a fault on your connection that is amplified by peak loads?
Suggest you connect to the hub, don't log in, but click the link for "check router status", and that will bring up a status page with five tabs. Post the content of the tabs titled Downstream, Upstream, and Network log in three separate replies here (as there's a character limit you may hit if you put them in a single post). Somebody will take a look and offer their view on what this indicates. If my suspicion is correct, and this is a line or area fault, then it's likely to get fixed far more quickly than over-subscription. If I'm wrong...well, you either sit it out for months and months, or you find a new ISP.