There is no physical advantage to using thinner wire for my "installation" unlike with some RV roof work involving several panels.
First I use up any wire I have lying around like jumper cables (like my 25 ft #1 gauge copper clad aluminum one) and other bits and pieces needed to reach the panel. Then if that isn't enough, I will wait till another set of fat jumper cables is on sale for half price and grab those.
Only thing wrong with my method is that the red and black insulation is now pink and black from being out in the sun so long. Just pretend it is 1955 and back in style! :)