You’re too early, no worries.
Exact schedules will be avaibable about 2 months before departure in Norway. Most people using the train only maximum plan 2-3 months ahead by train, usually even a few weeks or days in advance.
There’s also thee annual timetable change the second sunday of December (14/12), new schedules are probably not yet uploaded after that date. Some companies can be a bit late in that.
To get an indication of travel times and train services, just pick a random date next week. It’ll be probably very similar in November/December, just give or take a few minutes difference.
Best use https://entur.no to plan, and make your reservations a couple of weeks in advance. Maybe a bit more time in advance, if you plan to travel around the Christmas holidays to ensure seats in that busy period.
Getting all the way up north to Bodoe might be a bit dark. So you won’t see a lot of the landscapes, but you might get a chance for the Northern lights. Anything higher up north than Trondheim will be very dark, also during the day. But if you take day trains, leaving at 8-9 you should still see the landscapes with a bit of daylight in Southern Norway.
I lived in Bergen, and end of December/beginning January you can expect a bit of light between 9h30 and 15:30, 10h and 15h if it’s grey weather. The higher you go, the less light you get.