How bout pulling a trailer with a CX bike? I haven't yet tried this combo, but i've heard it works fine. Theoretically you don't need a stout touring frame because the trailer helps share the stress of the weight, and it allows you to have a shorter wheelbase and chainstays for a more responsive handling, lighter and faster bike when unloaded. And perhaps you might want to bring some thinner tires along too for those unloaded days.