I think you may have been there after September 1st? I have been working in the park for years and know most of the backcountry desk rangers pretty well and was still unable to acquire 2 nights at Stoney Indian during peak season (pre-Sept. 1st).
Negative. Both times were in July. Be flexible and honest those are good folks working those desks they will go out of their way to help you. Last time I did Cleveland we procured two nights at Stoney Indian then got two nights at MOK to do Merritt on the way out to Chief. All on a walk up permit. It's a great 4 night backpack and got to do two tenners on the way!