1) The only temperature critical stage of developing film is the developer. You can cool down your tank and a bottle of your developer using ice cubes in a water bath. It is not important to maintain low temperature through stop bath and fixer. It is even less important to maintain low temperature through wash. As soon as your temperature is below something like 140ºF you will be fine.
2) 220 film is more rare, and is only useful in situations when you are machine gun shooting, like in a wedding. Why not change the roll of film? It is not much likely that you would miss a great picture while changing a roll in most circumstances.