Here are the pics you posted the links for.
As to whether it will help -
Really you should have an UltraGauge or ScanGauge which can show you intake air temp. That way you can tell if the mod is raising the temp.
It also will help in showing whether its increasing your mpg.
WAI generally helps. Reduced restriction intake only helps if you're going for increased power, especially at wide throttle and high RPMs. Freer flowing intake isn't usually a fuel economy mod but ya never know.
My own WAI is based on holes cut in the bottom of the OEM air box of my '97 Civic HX. Because the air box is right behind the radiator it pulls warmed air once the engine warms up.
Your idea might work out, you have to test it. Looks like a low cost project with no permanent changes to the stock setup.