First congrats on the big score.

Second, I'd suggest keeping your bankroll intact as it is now and look for a certain win-rate over a certain number of hands in your current level before moving up.

I don't know what kind of multi-tabling you do or history you have but if you did 50k at 3 ptbb/100 at your current level, you'd most certainly be ready for the next level up.

The topic of bankroll size vs skill comes up from time to time, and this is a much smaller "issue" than most people seem to think it is. Ideal bankroll management guidelines are based off of two things: standard deviation and win-rate. Your SD will mostly be a function of style plus some variance, but your win-rate is mostly a function of whether or not you're playing well.

Anyhow, the point is that if you get a solid win-rate going over a good sample at your current stakes, then go ahead and move up. That should be your goal imo.

Good luck.