I figure it is too windy when I don't feel comfortable. I made the trip from Laughlin to L.V. on Dec 1st a few years back. We were ready the night before and should have left because of the forecast but didn't. Had to leave the next day so made the whole trip with a top speed of 35 m.p.h. and hit snow in Searchlight. Have had stretches on I 90 in MT. where we had to slow to a crawl and put 4 way flashes on until we could get off the interstate. My point being doable and comfortable are two different things. I lean more toward comfortable now.