They may survive in 15mph winds... but I can tell you from 4 summers up here in Wyoming that, you're risking severe damage in higher winds.
Any time you leave your awning out while away from the rig is a roll of the dice. Most of the time you'll be fine... but every now & then they're gonna come up "snake eyes".
All it takes is a single STRONG gust of wind from the right direction from a passing storm cell... or even on a clear-sky day... and you're risking hundreds, if not thousands of dollars in repairs.
None yet this year, but i've seen multiple awnings ripped off of various rigs here. Torn canopies, bent arms, and worst case... brackets ripped right off of the side of the rig, causing big-time damage to exterior of the RV. Even one case where the entire awning assembly then blew across the campground, and then into a neighbor's RV site, causing damage to their rig.
I have "wind-shakers" installed on my 2 awnings (think of an old pinball machine TILT trigger"... and I STILL don't leave mine out if I'm going away from the rig for more than 10 minutes or so. Just not worth the risk to me.
But I guess that's what it all comes down to: risk vs. reward