Well, I can pretty much answer my own question now. We brought the Elkmont home Wednesday. A total of 665 miles one way. It was a lot of driving in a 2 day period. Towing the Elkmont through southeast Kansas on state hwys was no problem, but when we made that turn west onto I-70 into a 30-45 MPH gusting head wind everything changed. I was fine at 55 - 60 MPH until a semi would pass me, then it was white knuckle city!
NO FUN! It lasted for about 250 miles before the wind dropped into the 20 mph range. Bottom line is that I bought an anti sway device today while they were on sale at Camping World. I may not need it all the time, but I DO NOT want to go through that again. The Elkmont has a lot I like over the pop up models, but ease of towing is not one of them. Also, I should add that my WDH was not set up optimaly for the Elkmont. I use a WDH with airbags, I was able to level the Elkmont, but the tail end of the Tundra was higher than normal. I'm not sure how much effect this had on the handling, but I'm sure it didn't help