When is the right time to take a new champion/role into ranked?

I'll try to keep this brief.

So this is my second ranked season (started playing season 2 but didn't hit 30 til/get addicted til the end of season 4). I've slowly been incorporating lessons from SS into my game- no raging, best decision based on the game and what my team is doing not what I think the best move would be or what I think they should do, watching my replays, and limiting my champ pool/roles.

I've been playing jungle primary and support secondary. Probably best at support (used to duo with the guy who taught me the basics who was an adc main, played support for a 5s team). Picked up jungle to impact more of the map and have more carry potential. My champ pool was way too big at the start of the season, but I've trimmed the fat to 3 or 4 jungles and about 3 supports.

But lately I've started playing Jhin in normals. I did it because he looked cool and I liked his kit and I don't let myself lose 3 straight anymore- if I lose two ranked games in a row I stop. I'll play normals or arams or do something else. Problem is, I don't remember the last time I had this much fun or carried this hard playing league. I don't think I've ever carried like this, actually (last two games were 15/2/10+ and 16/1/10+).

Problem is.. between Jhin and Ez, I don't want to play ranked anymore because I am enjoying these adcs too much.

How many games would you recommend playing on a new champ, or especially new role, before taking it into ranked?