In the first few messages try to establish a date, event, some meeting. Then you can just say, going to get my head down and focus on work, project, meeting, travel, looking forward to seeing you tomorrow!
If you don't have a established next step bur want to cool things off, respond to the last message. Oh, that's super creative, interesting, lots of think about. Brb I'm going to be away from my phone for a few hours