To have a solar system that will replace a continous load of 250w in most location in any season will be very large someting like 3 to 4 KW would be a good starting point. There is not enough room on even a large cataman for this much solar power.
A small generator is your your only practical solution if you want to provide this sort of power in the less sunny parts of the world.
If you are using the camera for 2 days. Then not using it over a longer period. The power for the cameras can be supplied by a large battery bank, with a smaller solar array gradually replacing the power.
The duty cycle is important, 2 days use and how many days rest? You also need to account for other loads such as lights etc.