McMahon stadium is not in the flooding areas of Calgary. It is at a much higher elevation and a km or more from the Bow river. Different tale for the Saddledome though which is drowing. Supposedly water up to 14th row seating on lower level. Dressing rooms, jumbo tron (was sitting on ice level floor) have major damage. It's definitely out of commission for at least a month or more, and then only partly up and running on a limited basis for awhile after that as many seats will have to be replaced, total cleaning, replacing drywall and so-on. Going to be a real mess at the Saddledome for a long time. The old Calgary corral might be in better shape, so the Flames might have to play out of there for awhile like they did when they first moved from Atlanta many moons ago.
Some parts of the light rail transit lines are underwater and some of the transit tunnels are filled up to the brim from photos I have seen. A great percentage of people who go events at McMahon stadium use the C-Train lines to get there. Electricity for most of downtown and many other areas of the city has been disabled until maybe mid-week so as not to blow transformers and start fires. I think most of the visiting teams stay in the hotels in the downtown as no really big hotels near the stadium.
So several of these logistics could affect putting on the game if it remains scheduled as is. Maybe delay it a day or two to hold it on the weekend instead? Will be interesting to see what is decided.