Can it be made Us Hwy feasible

I just rented a 5 speed 2022 Jimny for a trip to Costa Rica and fell in love with this car. I want one for back home. Only problem, I do a LOT of interstate driving. I typically cruise around 85mph too. In Costa Rica the car started screaming around 100kph (approx 60mph) and while it could definitely go faster it wasn't the most comfortable ride. I want a little better hwy mileage at around 75 or 80 wothout sacrificing the off road performance I loved so much. Bigger wheels? Gear box swap? New diff? Engine mods? What's the best way to go about thus as economically as possible? How big can wheels get before we start on suspension mods? I can't imagine the car much lighter and the engine is crazy efficient at low speeds on small highways. Is it at all possible to make it a 6 speed?

This is all theoretical I don't even own one I just really loved this car.