If there is one thing that comes from this that would be very smart by the teams with 10-30k empty seats per game - Have a blitz of cheaper tickets upon relaunch. Make it exciting and affordable at a time when people have been cooped up and are ready to burst out and watch anything with others to experience regular life again.
You could attract a whole bunch of new fans with "come watch a stamps game for $10 in the upper sections!!!". This could be an amazing opportunity amidst darkness to capture new fans.
But I know the Flames. If anything they'll do the exact opposite and try to raise prices to make up losses and lose even more fans. "You don't understand business - it makes more sense to leave those seats empty at $35 then have them half full at $10"