People get too pissy about styles. Let’s remember that most beer styles came from availability of ingredients and local water source. We live in a different time where sourcing anything we want from all across the world is available. So if you want to brew a kölsch with American ingredients and a lager yeast, so be it. Unless it’s in Koln it’s a “kolsch-style” anyway. If anything, it’s more traditional to brew with what’s locally available to you.
34/70 ferments well at ale temperatures anyway. Some brewers are using it for west coast IPAs even though it’s technically a lager yeast. I’d say fermenting 34/70 at Kölsch temps (58-62F) you will get the clean lager like character of a kolsch with a small touch of esters from the elevated temps. Ultimately, the beer is inspired by kolsch. To brew one traditionally, yes you need the right ingredients. However, if you want something close or inspired by kolsch, you’ll do just fine with what you have.