The only water that methanol would be sucking up in your fuel system would be whatever small amount of humidity that sneaks in during refueling. Otherwise, your fuel system should be sealed unless you’re driving something fairly old or you lost your gas cap.
Yet without the short term, there is no long term.
But then again, without the long term, there is only more short term.
In would already be at the saturation point from hygroscopic absorbion during the in-ground storage stage unless it was purchased in production-sealed containers.
The biggest problem I see for 100% use in a car engine is getting the engine started and warmed up, especially in cold climates.
I believe they used to start Indy cars on gasoline and filed the crankcases with heated oil to ensure immediate ignition and performance.