Do planes use more fuel at night? Well, you learn something every day.
Day VFR nav - climb en-route is fine, and not a lot more fuel for a piston than cruise.
Night VFR - flight below the LSALT en route isn't that smart, the safest option is to climb to the LSALT while in the airport area, before launching en-route. That's why the climb fuel mentioned in that post matters.