I'm in the same boat as you. If the car is too dirty for a waterles wash I take my buckets, water, towles etc and go to the self service wash bay. I just use the final rinse option for the water and everything else I bring.
I do my wheels at home so they are cool to the touch when I work on them. I use a hand pump pressure sprayer with a foam tip and Megs APC then another sprayer with water to rinse. I also put down the blue shop towels so I can catch all the run off.
Going to the wash bay early is a good idea, If I don't as soon as I start drying my car some one will inevitably pull into the bay I just used and the mist will carry over to the drying area making the whole effort counter productive.