If you want continuous video for months then you probably need a custom solution using a battery. The battery will have to be somewhat large (solar can help, but don't rely totally on it). LFP batteries like those made by Eco-Worthy might be a good choice, light weight, high power. A $30 battery box (sold for use with lead-acid car batteries) can protect it from weather.
Continuous video for months isn't really possible yet on low power because the camera sensors are not designed for it, current CMOS sensors would have to be totally redesigned. There are people working on custom sensors that are much lower power, rebuilding a camera sensor from the ground up, but it's high level research and I haven't seen that they are commercially available yet (the DOD may have priority, they would love to have long lifetime continuous video on the battlefield). They started working on them about 5 years ago and it involves new micro-fabrication techniques (Chip Elliot was involved), but they weren't entirely sure it was possible.
For time lapse check out the Brinno camera, it's made for time lapse, it has a waterproof shell, it can be powered from USB:
It can be set for automatic exposure so it gathers enough light to record at night (many seconds of exposure if your time lapse interval is long enough) while still handling daylight. It has a lens mount so you can choose wide angle or mild telephoto (maybe others are also available from 3rd parties). A time lapse Brinno plus a custom power system for a continuous video camera would probably at least make sure you get something with two independent systems. Redundency is good in unattended systems.
Continuous video for months isn't really possible yet on low power because the camera sensors are not designed for it, current CMOS sensors would have to be totally redesigned. There are people working on custom sensors that are much lower power, rebuilding a camera sensor from the ground up, but it's high level research and I haven't seen that they are commercially available yet (the DOD may have priority, they would love to have long lifetime continuous video on the battlefield). They started working on them about 5 years ago and it involves new micro-fabrication techniques (Chip Elliot was involved), but they weren't entirely sure it was possible.
For time lapse check out the Brinno camera, it's made for time lapse, it has a waterproof shell, it can be powered from USB:
https://brinno.com/
It can be set for automatic exposure so it gathers enough light to record at night (many seconds of exposure if your time lapse interval is long enough) while still handling daylight. It has a lens mount so you can choose wide angle or mild telephoto (maybe others are also available from 3rd parties). A time lapse Brinno plus a custom power system for a continuous video camera would probably at least make sure you get something with two independent systems. Redundency is good in unattended systems.