Bigger with louvers would be much better....they have no roof overhang to protect the type you show there.View attachment 1608117 A lot has gone on since my last post, but for what it’s worth, this is the type of vent holes I was thinking. Or you could simply cut a triangle in sheeting, hardware cloth opening on inside and attach hinges and a lock to cutout piece. Open/close when needed.
Just realized the quote as not from the OP.