Right now, with the tired 948, I can manage about 35 tops on the main freeway grade from my house to work (about 1000 or so elevation gain over a couple miles). I'd be pretty happy with 50, really.
I've been thinking some about supercharging, given the altitude (5550' up to about 8000' or so around here), but the cost is pretty steep. Once all those costs are factored in to my budget, I start looking at just buying a car with a much bigger motor.