The battery only lasts 2-3 miles if you run it as solo power. Prius can keep up at 80s-90s on highway easily. I've driven it over 2000 miles on one trip in the summer time and got average 43 MPH including climbing through the Rockies. The speed was maintained 75-85 most of the time. Love it!
In the past, I have driven 6 different cars to some ski resorts west of Denver including far out-reach ones. If you drove on I70 between Denver and Grand Junction, you would know what I'm talking about. There are quite a few long steep climbings...tight curved roads. All of the cars I drove went through ok without pulling me over.
V6 sedan has no problem, but can be a risk if it is heavy snow weather.
Old V6 SVU was sreaming when climb steep uphill roads. Lack of power and soft suspension made me feel less confident while driving.
The Prius had some challenging spots. On a couple of steep uphills, the battery went completly to zero before climbing end. But it still kept climbing. Speed was down to 50s. Those uphills were not very long. 5-10 miles? So the car battery could get quick recovered after that.. and drive as normal.
The other V8 SUV went through fine. The last one... my sport V8 SUV handled perfectly. I was able to pass everyone on all the curved uphills. Although, the gears still went down to 3rd or 4th and rpm reached over 4000 on some tough passes ... if I remember right.
From my past experience, I would say that Prius is capable driving on any long distance drive but on thick snow covered condition. Its traction control can not be turned off. Sometimes, it causes problem.
However what you drive is absolutly personal preferencees. I'm not making recommendations of what you should drive, but technically speaking, what car is capable doing what you need.
