valdattaMadun says:
I think the concept is if you are averting your gaze shr has advantage. If you dodge she has disadvantage. So Dodging makes it a straight roll
Yes, this is what I am referring to. You are averting your gaze, thus she is effectively invisible to you to avoid the Con save.
If you dash or dodge, she will take an opportunity attack, though with dash she will have advantage and with dodge it will be a normal roll (adv. & dis. adv. cancel out). If you disengage, she will have advantage on attacks during her turn but you won't trigger the opportunity attack.
As for for the ranger, I'll say he can grab on to you with his reaction, though since he didn't hold his action to do so he isn't riding so much as being dragged along.