I've seen that, but I find that hard to believe. It's an NFC championship game, no season ticket holder is going to give that up. The Lions, although they have dedicated fans, are based thousands of miles away. I'm guessing it might be 5%, or 3,000 people.
By the way, the cheapest re-sale seats have come down, not unexpectedly, by around 25% from Sunday night. Plenty available in the $450-$475 range (before TM fees and tax) for people who want to just get in the door.