There was no possible way they could follow the girl down that road without being made. And they had no idea who or what was waiting for her at the end of it. If he was alone, Derek would probably go on foot and at least get the lay of the land, but he didn't want to put Judith at risk and he knew that she wasn't going to let him proceed alone.
"No, let's leave it for now," he said. "Find out when she works next and we'll set something up."
He would scout out this location later though. Or send McCall and his Pack to do it. The more intel they had, the better.
"How about I buy you that Americano? You can ask whoever is working when your good friend... uh, whatever that chick's name is... works next since you're so bummed about missing her today."