3 years ago, I pulled my campoer over the mtn passes with no supercharger, 33's and stock gears. The passes make you go slower, but there isn't any other problem doing it. I would not spend the extra money to bring another truck to work through just a few slow spots. Think you are over worrying this.
Sure people will be passing you on the uphill climb, but that gives them more time to see what a cool truck you have