I want to continue to take the high road when she goes off.
I suspect she's going to call me names, rewind the tape, blame me for all of her unhappiness, etc., etc. I'm trying to prepare myself for what she throws at me.
I'm thinking act "as if" everything will be fine and go in with a positive attitude, don't get defensive, however don't take any unnecessary verbal abuse.
I think you've got it about right. If she's downright rude or disrespectful, just stop the conversation and say "We'll continue this when you calm down and stop being so rude. You're upset right now and I get that, but I'm not going to stand here and be treated so disrespectfully" (or something similar).
If she keeps it civil, just say things like "I understand you feel that way. Everything I'm doing, I'm trying to do what's best for the kids and myself. This is what I've decided is best right now."