So swapping batteries every 2 months instead of every 1 month is going to make you happy? This of course makes the huge assumption that the XT2 battery will last twice as long as the XT1 battery did. Great in theory but real world performance is yet to be seen.
You may be better off selling XT1 and then buying a wired system. Yes more of a pain in the butt to install, but once it is done, so is the battery issue. Wire systems (or wireless IP and AC powered) cameras record all the time and save the video to large hard drives. They have come way down in price over the last couple of years. They are also way more feature rich than Blink.
If you have lots of activity in front of the cameras that is killing batteries every month, Blink is actually not the correct product to buy. Hindsight is 20/20 as you now know. Google wireless IP camera system for more info.
If you have to stay with Blink, then run power to each camera via that USB cord outlet. Bottom line there is no long battery life with lots of motion detection.