If you're learning the do's and dont's, then heed this. NaOH, or Sodium Hydroxide, or Lye, is extremely caustic & extremely reactive with metals. It will eat through aluminum like hot butter & can also eat away at other coatings used on cookware(was a professional cook for a large part of my life). Never ever should Lye be used in combination with metal, unless that metal is stainless steel & it is a spoon you are using to stir your NaOH solution in a GLASS jar. Separating into smaller jars is perfectly fine, I plan to split my next batch into two jars for easier decanting later on (have small jars too). The only thing is that you need to be sure to split your solvent between your containers, don't flood them all with the amount the recipe calls for, split it three ways just like your aqueous phase was split three ways. Or else you're going to wind up with quite a bit of evaporation to do.
The best option here is to split it, or buy a new(bigger) jar. Don't mess around with Lye & metal, it isn't worth the risk.
Enjoy The Rocky Mountain Sky 