I can't imagine that happening for a lengthy period of time at all. Ultimately for the premier league some money is better than no money. Didn't Sky commonly use that logic as their bargaining tactic in years gone by? I recall them not agreeing terms with some sporting bodies until virtually the day before the season/event began. Ultimately they knew that no one else could feasibly take it on in NZ at the time, so they used that leverage, and why not, it was a great strategy.
If the current price point becomes untenable and no one is willing to pay it, then no one will - and it's not untenable UNTIL no one is willing to pay it. The ball would be back in the premier league's court then, to decide if they want something, or nothing at all.
Call me naive but I imagine they would probably at least want something out of it.
Is there anywhere in the world where the premier league is not accessible due to rights going unsold, despite there being some demand?