I guess I am wondering how haveing a split oil tank is not a much bigger problem....but...
As far as removing oil/grease, the chemistry involved is getting the oil/grease into a solution/solvent. There are plenty of solvents that will work on their own, but they are typically a fire hazard, will etch/dissolve paint, plastic, rubber, insulation, etc... or both. Even the degreasers that are "stand alone" have water mixed in, as it is the cheapest and least harsh solvent. I can go into the chemistry about how soaps/degreasers work, but as far as what is safefest for the rest of component of your ride, water is it.
Maryland is supposed to be in the upper 40's today, so it will be cold, but not freezing. As someone else posted, be very careful with a degreaser. They can pit aluminum, fade plastics and rubber (they are made from "oils") and make vinyl and leather a mess, depending on chemical make up of the degreaser, the contact time and the ambient temperature.
Perhaps you can hook up "hot water" from a hose connected to a washing machine supply line or a "sanitary sink" with a threaded faucet nozzle. Relatively hot water rinse and hot water in your wash bucket should help evaporate most of the water and buy you some time to wipe the bike down it the air temp is below freezing. Plus, the kinetics of hot water dissolve oil/grease (and just about anything) much faster the cold water.