Kolsch Question

I'm making a Kolsch with Wyeast 2565 in a few days. I can get an ambient temp in the 65F-68F range in my basement. Is that going to be too warm? The Wyeast site says the strain can go up to 70F, but I've heard here I'm better off in the low 60's. With 65-68 are we talking a minor difference or a completely different brew? (Yeah, I know I can swamp cooler it, but would rather not if it's not going to make a huge difference.)

I brewed a Kölsch with that yeast earlier this spring, and had challenges keeping it on the cool side. Essentially the fermentation temps I got were between 60-66º by placing the fermenter in a water bath with ice packs. I would just change out the ice packs when they melted. The beer came out very, very good. Your temps will be OK, but I have heard that the upper end of the 2565's range can produce more fruity characteristics. Try to do the water bath trick, or put wet t-shirts/towels around the carboy then point a fan at it.
I would try to keep it under 65º if at all possible.