you are asking too much out of a bike, hahah. comfortable on highway for hundreds of miles, then maybe single track, oh yeah 2-up as well.
the bottom line is if you never did dirt you need to start small, period. You will be struggling with anything else, even a dr650. Just a few hours of practice on a nice 250 is all it takes to really understand what is possible and what isn't. Plus it is just plain old fun, you really have no idea. On a KLR you will be too nervous just to not fall over. I know you want to get what you want right out of the gate but you need to work up to it.