I'm also planning to view the eclipse, but I'm not expecting much delay as I walk out into my backyard given I happen to live right square in the zone of totality.
What I can share is my experience when I took my 2016 MS90D in August 2017 to see the total solar eclipse.v That time I drove from central Indiana down to the Kentucky/Tennessee border. Back then the only supercharging spots along I-65 were the original Louisville, KY and Bowling Green, KY superchargers. Going down I stopped at Louisville to charge and it was already busier than typical. I didn't have to wait, but charging was slow due to the paired stall impact of the early V2 superchargers. This was even with what I thought was getting there "early", arriving at my viewing spot a good 2+ hours ahead of totality and any beginning of the shadow progress across the sun. Traffic getting there wasn't bad, arriving as I said early, before most starting filling into the area where I stopped.
The actual period of totality is quite short, only about 5 minutes. Many started to pack up and leave pretty quickly, others like me stayed around for a while before deciding I was going to set off for what would normally be about a 3 hour trip back home.
What I immediately saw via my navigation is essentially a solid dark red line along I-65. What I ended up doing was taking a back way via secondary highways up to the Bowling Green supercharger. Supercharger there was full, with typically a couple cars waiting for a spot to open. That is the only time I've ever experienced that supercharger being totally full. I was lucky as a spot opened up right as I pulled in, but again, due to the shared stalls, charging speed was slow and the stop ended up taking about twice as long as I'd anticipated. When I went to leave Bowling Green, traffic along I-65 was still largely at a standstill / crawl, so proceeded to follow alternate routes via state/county roads to weave my way back north. I did ultimately make my way back to I-65 by about Louisville, but the overall drive back was something more like twice the amount of time that it should have taken.
So, whether you take your Tesla or your ICE vehicle, I'd trust the predictions that traffic will be a mess, especially the closer you get to the zone of totality. This of course also depends a lot on the weather, as if it turns out to be an overcast/rainy day, expect a lot less people to make the trek.
Good luck.
, at least until totality, but at that point you don't want anything between your eyes and the eclipse!
