Good responses from the contributors here. I second the notion that a bit more than 500' over the tops would be preferential, for all the reasons provided above. Forecasts aren't always that accurate as I'm sure you're aware, would want a bit more fat built in. Don't push it, always have an exit strategy. Read up on mountain waves, crossing ridge lines in strong winds, etc. Make the decision to turn back early. But, I'm sure you won't have any problems, the area is really picturesque - any snow up that way yet?
Refreshing change to see the positive, encouraging responses from people on here.