A lot of highly voted comments were removed from this answer and others. Instead of deleting them, and asking people to move to chat, why not auto-archive all such comments and move them to chat so that they are not lost? May be create a new chatroom for that answer.
Edit. Thanks to jmac for this discussion link
My idea is to have a separate chat "page" for each answer. There could be X comments on the original answer. After say 24 hours are done since posting the answer and mods have started cleaning up the comments, they could activate the chat "page" that will auto-archive all comments. Then can then remove comments that think were not good enough to be on the main site. Score of the comment will be visible on the chat page.