With no tilt/multitableing game problems... you need the exact same bankroll.

But, a normal person will need to adjust at some point.

Personally, 2 - 4 tables of ring or 2-3 tables of SnG/MTT and I dont need to adjust my bankroll requirements.....

After (and before) that I do need to adjust because I cant play them as well on autopilot, and I cant play as well bored.

That makes my BB/100 and ROI drop because skill becomes a little less of a factor, and luck becomes a little of a factor.

I actually play my best when i'm 2 tableing.

Other players are diffrent.

You will really need to figure out the answer to this yourself... Start with the standard rules as a minimum... and move up from there as needed by looking at how your ROI and BB/100 number change as you play more tables.