So this season corrected my single biggest issue with the league system, the queues. They are now at most 2 minutes and can be done on any map (vs. 10 minutes only in heart of the mists), so I can finally be bothered to do these achievements towards the legendary backpack.
But it looks like I need 60 total days to actually get it! There aren’t that many days in the league, am I out of luck?