I really liked this as a finale. It started a number of plot lines to be continued next year.
MAJOR SPOILERS, skip the rest if you haven't watched it yet.
I wish June had urged Serena to run, too. And I think June's 'renaming' her baby Nichole was to honour Serena's sacrifice, and her silence. All Serena would have had to do was scream and all would have been lost. I think June is going to either go to one of the Marthas or to Cmdr Lawrence. And I loved the scene of the Marthas 'handing' June off to each other as she made her escape through their various backyards, right under their Cmdr's noses. Very Underground Railroad! And HELL YES, Rita, you kick ass!!! Who thinks, like me, that the house fire was set deliberately by a Martha? And what's going to happen to Nick after the way he subtly threatened Waterford?
The bit with Serena and the other wives and Serena's 'punishment' was (no pun intended) bone chilling. I think, unfortunately, that it's killed whatever spark there was in her. She's given up. And the scene in the kitchen with June and Fred about 'obedient women' made me want to vomit!
I have a feeling Aunt Lydia is dead, ambulance or no. If she wasn't dead when Joseph came in, I think he finished her himself before he got Emily out of the house. He couldn't risk that AL heard or saw anything, even though she appeared unconscious. And don't ask me why, but I think that Emily is going to keep the baby herself rather than turn her over to Luke. She has no idea where he actually is in Canada, knows that he has no bio tie to Nichole, and is unsure of what his life is now. She may also figure it will be easier for June to find her (Emily) in Canada. Of course, that's assuming she makes it there!
I did notice another hint on the timeline. Emily said it was her son's 7th birthday. IIRC he was a toddler at the airport, not an infant. So that means we are around 5-6 years into the main 'crackdown' in Gilead.