Thank you all for the responses - it really helped my comfort level with the truck's capabilities. We're going to stick with this truck for now and we now have some things to try and best of all we know what to expect when we hit those grades.
In a few years when we're really ready to upgrade we'll definitely do our homework and figure out what the best options are at that point. Hopefully the current shortages will be long in the rearview mirror by then.
In the meantime, thank you all!! This has got to be one of the most helpful groups I've ever encountered.