Lucius didn't have to be told twice. Instantly he appearated to go warn his family. Putting up the rest of the protection charms wouldn't suffice. He wasn't sure what they could do at this point since none of their magic would work against a dementor. Not when their magic was aligned with the dark. That's what frightened him the most.

He was hesitant to rely on Remus's help knowing their history together. Then there was the little bit of pride he still had left. This was his family. He had to protect them. He managed to get them out of the mess he caused from the start he could get them out of this too.

If necessary there was another place they could flee too that was isolated like this one. His family followed him with questioned, all them having their wands out. Warily, he led them out where Remus was, unsure of what to do at this point. He hated being in such a position.