Will you be out I-84, or .....?
Specifics would depend on your elevation, soil type, sun exposure & whether it's a sheltered location. Not all zone 6 areas are the same; what they do have in common is typical low temperatures.
That said there are many trees to grow. Another question: what is your vision of the driveway? All trees, or possibly some shrubs tucked in here & there? Having both allows for more bird habitat, as well as a staggered flowering season, which is good for the various pollinators, and very pleasant for the eyes.
Let us know as much as possible. I am particularly biased towards trees & shrubs, if one has the space: gives the property an entirely different dimension!
