Have you considered cattle panels as your structure. Their 16' long by about 4.5' tall. If your making it 10' cut offs can make your ends. Assemble as an a frame with about 30" opening at top and 5' width at bottom. Very sturdy and heavy guage galvinised wire lasts forever. I use fastgrass backed w poultry netting to cover mine with bundles of tall grasses but a few limbs from local trees could also be used to break up outline. You can hook wind blockers to wire if needed but I,ve found the fastgrass itself to be sufficient. Frame can be moved around easily and if you back your panels with plastic netting they can be rolled up and taken away when not in use.Bring your brushing high enough over top to somewhat cover top opening.