NHLPA Executive Director Donald Fehr has said that the Union would have no problem with the NHL season starting without a negotiated CBA. Here's what Fehr said:
Want a precedent? MLB owners started the season in 1994 without a CBA. The same Donald Fehr was unhappy with the offer on the table (which included a salary cap and rollback on free agency eligibility), and the players went on strike on August 12.
The rest of the season, including the World Series, was called off by Bud Selig on September 14. The move to cancel the rest of the season meant the loss of $580 million in ownership revenue and $230 million in player salaries.
There is simply too much to risk for owners to start the season without a new CBA. That scenario is just unlikely. No grey here.