I have a spare one-gallon hand sprayer for my yard which I keep full of water. After any salty ride I spray it down, then I blow dry with my air compressor.
The idea of having all the extra hassle of another bike has kept me from going that route, you can spend a lot of time cleaning one bike before it is worth it to get another which you need to get the fit adjusted, keep lubed, tires maintained etc etc. I do have an extra set of wheels with studded tires but they only take a few minutes to swap in. Plus I only want to run studs when I absolutely have to, I hate the ride quality.