Some of those that are near the mid 250s would be risky, especially as the car is likely to be loaded down with above average mass, maybe some bikes or a roof luggage unit hurting aero. Guess you could drive slow.
I saw several Teslas around the park, and I think it's doable if you only want to visit say 1 or 2 locations, but without a Supercharger in the middle of the park, you will be limited and won't have the flexibility to see everything.
The resort in the middle of the park has 4 J1772 chargers, which would help if you were staying in the park overnight, but we were simply doing day trips.