The current patch is 14.6. The next champion is the next newly released champion after Smolder (not counting champion reworks).

Patches typically come out on a 2 week cycle, and are numbered [season number].[patch number]. For example, if the next champion came out in patch 14.10, the question would resolve to 10.

Resolves 27 if no new champion is released for the rest of the season (which should end with 14.25 or 14.26)