Understand your pain. I wrote about my short day crop of sweets with a similar problem. I found the tops to be amazingly delicious...so already have eaten or processed the 80 short day sweets. I did not wait for wilted tops. Mine were already from 1-4". Were your onions sets or plants? My main onions are from plants and the sets are for greens. If you still have some sets, plant then on the lee side of taller plants for improved possibilities.

Next year, I plan to use a 12' pallet fence (west side of beds) until the onions are harvested-end of July for sweets in my area. Just now the long day storage onions are east of the pole bean bed- no damage so far from errant storms.

In a similar windy site, the potato onions and shallots showed little suffering, as though the stems have 'elasticity.'