So, to follow up… I successfully completed my 100 mile attempt, this morning!
I did end up using “It Seemed Like Thin Air”. I did it on 80% in Level 2 (no way was I doing this in ERG mode). It ended up being nearly perfect. The end of the first time through was hard, but I was mostly thinking about how hard it was going to be the second time through. Still. The first time I did this video was back in April or May during my very first training plan and I managed to do 44 miles while riding the video at 100%. Today, on 80%, I managed to do 45 miles on the first pass and 43 miles on the second.
The second time through was definitely harder than the first. My legs didn’t respond as quickly. It took me at least a second or two longer to build up to the target power, and a second or two longer to stand up when it told me to. And I did skip a couple of those - partially because I was on 80% and every time I stood it was hard to keep my power from way overshooting the target power. Sometimes standing up helped me get back up to target power when I was suffering and drifting too low. But sometimes I would be in a good rhythm and standing would throw me off my rhythm.
My legs were definitely tired the end of the second time through the video. but, once I hit 93 miles, I definitely was starting to crack. I had to push through a few points where my legs gave our briefly. And it may have actually been lucky for me that I dropped my chain when in the 25 gear a couple times in the last few minutes because it gave me a few seconds of rest while I managed to ride my chain back onto the big ring on the front. Shortly after the 2nd or 3rd time in a row and switched to the small ring and a middle gear in the back. For some reason that was mentally harder than the big ring and the 25 gear. I don’t know why.
OMG. And at the very end of the 40 minute climb at the end, when you have an uphill sprint finish against The Shark! This screen would come up and BOTH times - even on the second time through when I was at 87 total miles - I somehow managed to squeeze out 260w for the build up and then old over 400w in the sprint (that’s a lot for me, lol). It was a crazy intense rush of energy and euphoria. And then BOTH times I ended up sobbing into a towel for the next minute for no other reason whatsoever.

Oh! And one of my favorite other video moments is a few minutes before on that same climb. I can’t help but laugh out loud when Kruijswijk and the two other riders all simultaneously look back at Nibali and the video pauses and they say “STOP PLAYING THAT STUPID MUSIC EVERYTIME YOU CATCH BACK UP TO US!” It totally throws off my concentration when I’m working hard at the end of that climb, yet I love it and can’t help but laugh every time. 
I do have one small yet big request, tho. Not sure if this is a bug or a feature… lol, but… I was at 99.3 total miles and rolling up to finish the full 100. And I was planning to take a picture of the screen showing 99.9 miles and send it to my dad and say “Done!” And then send him a text a compute minutes later saying “just kidding!” with another pic a couple minutes later of it showing the full 100 miles. HOWEVER. I couldn’t do this because shortly after I hit 99.5 miles… the screen rolled over to round up and show 100 miles. Not only that, but it also doesn’t show the decimal places once you hit 100 miles. Sooo… I actually ended up riding until the screen shows 101 miles which turned out to be 100.58 miles to make sure I actually for real didn’t end up riding only 99.6 miles. This really should be changed, IMO. 1) Don’t round up to 100 when you hit 99.5 or 99.6 miles, and 2) Please keep the decimal when you hit 100 miles!
But, anyway, other than that, and cracking multiple times with only 7 miles to go, it was great! I got down 3 or 4 times to grab more drinks, but only for like 5 seconds since my trainer is in the garage right in front of the spare fridge. Other than that I only stopped once to change my socks. Despite drinking and eating a ton, I never had to stop for a break. Which reminds me, I need to get something to drink, right now.