If he takes to his horse and gallops in, I'm going to say he can get on the scene in 4 rounds. That's actually probably a little too short a time frame, but I don't want to cut out the possibility entirely.
Don't forget to describe the path he needs to take if doing this.
In response to Abn's query, between Fay and Velon, Poljen should be up at 17 HP. Lia did not state she was healing the barbarian, but she still has a bonus action for this round if she wants to send another healing word his way.
Edited: daishain on 2nd Jun, 2017 - 1:33pm
Welk however we do, I'm ready to have Geoffroy be a "Big Damn Hero". Though with his horse perhaps being "The Cavalry" is more appropriate, with him rushing in there to help his companions… I spend too much time on TV Tropes.
The question is whether or not this would be because of a sending cast by Lia or for another reason.
Edited: Thomaslee on 2nd Jun, 2017 - 3:40pm
I wish there would be some way for Geoffroy to come to our assistance without using a spell slot. I don't know what it would be though. One issue is that we are in an area that he has never been in before. I don't know how he would know where to go.