The solar cells used in the folding solar panels are made by Sunpower and they are 23% efficient.
If you had 6 panels you could wire 3 panels in series to get a higher voltage and then increase the solar panel cords to 75 feet without seeing much voltage drop. Doing this would require you to have even pairs of panels so each set of solar panels are equal in number so they output the same voltage.
I'm placing an order for a new batch of solar panels this week and they will be on my doorstep in 20-30 days.
Expected build, test, and ship time