The only thing necessary is to stick it in MM before you get to about 15 miles range left. Then the Volt will maintain the battery at that level with extra battery power in reserve.
With that extra reserve, the Volt can climb any grade in the US, at any speed you like, with virtually no dropoff in speed.
I drove up the Grapevine in southern California with the car set at 75 mph and a fully loaded car, and the speedometer never dropped below 74 mph for the 15 mile grade. Another Volt driver posted the same thing, except he maintained 90 mph, and never dropped below 89 mph.
When you consider that most of the the other EVs can barely reach 85 mph on level ground, the Volt's performance is truly exceptional. Most other cars with automatic transmissions end up having to downshift one or two gears and slow down just to make grades like the Grapevine. And, you can hear them straining their guts out trying to maintain speed. The Volt, on the other hand, handles mountains effortlessly. You will be impressed, trust me.