AIPA with Kolsch yeast starter question

Hello-
First time using wyeast kolsch yeast. Using it on a AIPA. Need help on whether or not I should start, starter with 1L then bump it up next day to 2 or just make a 2L. Mr. Malty says 1.4L with 2 packs but I only have one. Thanks for help.

There's a slider at the bottom of the Mr. Malty calculator that lets you adjust for fewer yeast packs (slide it all the way to the right for larger starters). It should update the starter size you need. If you've already done that and it still says 2 yeast packs, no problem stepping up a single one. All you're trying to do is to increase the cell count. I find it easier to cold crash the yeast and decant off the spent beer, then toss a new starter on the yeast cake.