Please God, no cliffhanger. It'd be so much better with Rick's "I will kill you one day" line (I'm paraphrasing, obviously) and Negan riding off into the sunset after a "Ta-ta".
This also keeps them from having to linger at the site of the killing too long afterwards, because I worry they'll mess that up in some way and it'll feel awkward to see them either continue taking Maggie to the Hilltop or returning back home, etc. Ending the season with their encounter finished and then starting season 7 with everyone back at Alexandria and the Saviors coming to pick up half of their shit seems like such a better, more logical, and evenly paced way to go.