It could be targeted, and I'm not sure if it applies to monthly or non-Family license types or is renewal-date-dependant, but unfortunately there's no way for me to tell aside from posting it and see what y'all discover. Apologies if I've wasted your time, and hopefully the post meets guidelines.
Instructions to get there:
1. Go to your Microsoft account that has an active (annual?) MS 365 Family subscription currently. (You can get there from the Microsoft 365 app on your PC, or log in via www.office.com)
2. Click on your profile menu (top right) and click "My Microsoft Account"
3. Under Subscriptions, find your Microsoft 365 Family subscription and click "Manage"
2. Click "Turn off auto-renew"
3. There should be a call-to-action titled "Get two months at no additional cost" near the top of page as per the screenshot
4. Click "Extend for two months"
5. Confirm to continue, renewal date should be pushed out by 2 mths.
I'll update info based on feedback in the comments, thanks for reading.
I think this is a long running deal.
I haven't done that maths but I think the save on IT subscription packs end up cheaper still, especially when they're on sale (as they are at the moment)