Yeah, it's hard to pinpoint exactly what revenue is/was and therefore make any accurate statements for this season. At least before anyone could easily find HRR by using the salary cap figures, but that's now thrown out of the window with the flat cap.
I do know that the current yearly revenue from television deals really are worth a lot less than what people think. Just taking a casual look:
NBC deal (up for renewal at the end of this season) (
NHL, NBC sign record-setting 10-year TV deal)
$200 million (USD)/ year
Rogers deal $5.232 billion (CAD) for over 12 years (
NHL, Rogers announce landmark 12-year deal)
$342.5 million (USD)/ year
So the league makes about
$542.5 million USD total in national TV deals this year, or about half a billion only.
Even accounting for local TV deals for all 31 teams
And adding in sponsorships/advertising fees/merchandising
That's still a long way to climb without attendance.