A tarp will be a huge kite, nothing you will be able to do to keep it down. Tying it most likely it will shred in the monsoons, mine did. I have tried it in other applications here in AZ, doesn't work. I used the ADCO covers during the summer as we do not camp between the big 2 weekends. Though even with the heavy duty ones they only last one season, the heat kills them. I do the CW "warranty" so that every other year it is "free" so in essence I get them for a little over half price. This year I need to try another more durable brand. I've looked at some that others use here on this forum and their samples don't look all the much better at over twice the cost of the ADCO. So far this year it is uncovered.
I feel we need to cover in the summer months here (only if you don't use it) but I am out of ideas on what to use.
2014 Arctic Fox 30U
2001 Silverado 2500 HD, 4WD
8.1 Vortec / 4.10 gears / ATS Stage 2 Allison Transmission with Co-Pilot
Tekonsha Prodigy P2 Brake Controller
Reece Class 5 Hitch with 1700lb bars