Technically, you can fly between just about any city within the US after skiing a good portion of the day and still be in bed at decent hour to ski the next morning. So, in a perfect world, flying beats driving time-wise hands down.Not in the case of SLC to Reno. The airport is relatively close to Snowbird and it's a short flight so you could easily ski all day, fly that evening, then ski at Squaw all the next day. You really do lose a day of skiing by doing that drive across the Nevada desert.
In practice, you have to return your rental car, pack up your ski and check it (fingers cross it gets to your destination airport), re-hire another rental car at your destination airport...
While all that doesn't take 8 hrs, the stress level CAN BE high.
And if there's a storm anywhere near, you may find yourself stranded for far more than 8 hrs! Speaking from personal experience here.