I usually setup my repair stand in the entry way and place 2 boot trays under the bike to catch melting snow and water I used for cleaning. I also use the boot trays when doing maintenance to catch greasedirt clumps falling off the drive train, get that on your socks and you'll have grease streaks on the floor / carpet.

For the most part if its warm enough that my bike needs a cleaning, it is warm enough to wash it outside. If its too early / late in the year to have the garden hose hooked up, I'll use one of those hand pump 2 gallon chemical sprayers for rinsing.