The Hag does try to flee, the grease spells keep her from getting far. I have even had her abort the exit and try to fight my party--when she DOES somehow get up. Also, to modify the strategy somewhat to make it even easier, throw a 3rd grease spell (or bottle) in the doorway of the Tea House as well...slows down the redcaps. Then you can spend a couple rounds bombing in spells to help get the Hag down faster.
No, something is seriously wrong with her AI right now. She used to go invisible and "aggressively" flee after one round and she would misty step out the back room. We used to have to kill her using the Wyvern poison and it was a near-thing every time.
recently after the last two patches she uses the invis potion, and then will forget she is fleeing and attack someone. I have even stopped attacking her and backed off and she will proceed to make physical attacks against my team even when we stop attacking. It's actually harder to get her to flee downstairs than it is to kill her in the teahouse.
The only way i did it recently was to go past the fireplace and force her to spawn downstairs. I think it's unfortunate as the fight downstairs is much more dynamic and interesting than fighting her in the tea-house since she uses almost none of her abilities or tricks in the tea-house.
Also she is an incredible potion resource - best in game.
