Mobile Coop Open Design

I am building a chicksaw similar to the one in the picture. It will be 4 feet by 6 feet, with the front being the 4 foot side and open with hardware cloth.

I am concerned about too much rain or wind getting into the coop. Do you think it is best for the mesh to go back 1 or 2 feet on the long sides, like 1 foot of mesh and 5 feet covered on the long side, or 2 feet of mesh and 4 feet covered, or something different?

Any ideas?