Hi,
Your goal is certainly challenging and definitely unique.
I cannot give any advice on routes as it's alien territory to me, but I can emphasise that the advice to date is good and based on broad and deep experience.
I can give advice on charging options as I have researched them myself;
There are generally 3 different options for charging while on a bike;
1. Hub dynamo with an adapter to charge via usb. Only works above a certain speed and is not cheap to put together an adequate system. Most people use a powerbank charging from the usb port and then charge sensitive electronics such as a phone since the varying speeds can mean intermittent charging and phones stopping the charge at low speeds and not starting to charge when speed picks up.
2. Solar. Not terribly effective on a moving bike. Handy when stopped and able to manually adjust to maximise sunlight. I have a 3 panel unit that is a backup. But winter effectiveness is minimal.
3. Stopping and charging "on the road". As pointed out, some purchases may be advisable. And in winter, there may be less options open and available. Also, in winter, every hour spent charging is one hour less of daylight for cycling.
I have never come across a generator that works off braking as you have described. That is not to say that it won't work, but I would strongly advise that this is both weatherproof and tested "in the field" before you find yourself in an area with few people, a problem and no charge on your phone.
I can also give advice on Winter touring;
As stated by others, a big issue is daylight, or rather the lack of it. This is not an issue of toughness, it is an issue of daylight. Simply, there is less time to get from A to B. In mild weather, not getting to my destination can be uncomfortable. In winter weather not getting to my destination can be fatal.
In winter I travel slower than normal. I am packing more weight - clothing and food and also need to regulate my effort to that I am not sweating too much. Too much heat generated when I am cycling will quickly turn into too much cold as soon as I stop.
There are also issues with road surfaces and snow or sub-zero temperatures.
Slower travel can also have an impact on charging abilities.
There are many blogs on CrazyGuyOnABike that cover travelling in winter, or in very cold locations. On Youtube too.
I wish you the best of luck in your adventure.