What are your plans for energy conservation and power sources?
I occasionally hear of some newer type chargers that can power up a power bank really fast, but that has not been my experience. And I have heard of people that rely on solar panels, but I have only once actually met someone that laid out solar panels in a campground to charge things up.
Last summer, for the first half of my five week tour, I was self reliant on dynohub charging up my power bank, but as time went on my power bank power level kept decliing. I eventually figured out that I had a cable with high resistance between my dynohub/usb charger and my power bank. At that point fully charged up my power bank using the power supply in the laundry room at a campground and changed cables.
The next couple of weeks had no problems at all, finished my tour with all four power level LEDs on my powerbank lit, meaning a high level of charge.
Some suggestions, (1) use good cables, (2) minimize screen time on phone, (3) stay in airplane mode on phone or off as much as possible, and (4) only use a phone that is warm. I found that when I got on wifi to check the weather forecast in the morning, if my phone was in the 40s (F), my phone battery dropped power level a lot faster than when the phone was warm. I started warming up my phone in my sleeping bag before using it on cold mornings.
If you are interested, I wrote up what worked for me for power usage, inventory of electrics, etc., on a different website after my five week tour last summer. Yeah your tour is more than ten times longer, but if you have not given thought yet to your electrics, you might want to look at my summary. That write up is here:
Electrics that I use for bike touring - what works for me.