I got some more information from James Jonsson about his Lake Tahoe attempt, it sounds like it was quite an adventure! I was happy to hear that he has not given up and will try it again someday.
After the Tahoe attempt I was able to get a few facts about the conditions I experienced. My pace for the first 1 1/2 hours was 2.58 mph. My last hour only covered 1.48 miles. I burned through 4 kayakers who could no longer put up with the conditions. At one point one of my kayakers saw me go airborne as I lunged across the top of a wave and then had to dive under the next one. We went backwards 50 to 100 yards at each feeding stop. At the start of the swim the air temp was at freezing and there was a layer of frost on the boat. Water temp was 63. When we got back to the boat ramp it took us 3 tries to get the boat on the trailer because the wind was so strong it kept blowing us off track.That was a tough and windy day. I will be back someday and try again.