An elder statesman certainly can be Vice President. A White House Chief Of Staff should be much younger, because the actual duties would be more demanding--energy-wise.
Newt could handle Chief of Staff responsibilities and not break a sweat. He and Trump would hold court at 9:00 am every morning and write legislation to eliminate a half dozen cabinet departments, agencies, and anything else that’s destructive to our Republic. Newt would see to it that Congress signs off on the bills and Trump stamps his signature of approval. Done.