I think it will be likely you will struggle to go past 12,000 feet or maybe 14,000 feet. As Klaus noted, the research has show the brain struggling at only 8000 feet (2700 meters)

Taking time to acclimate to the altitude will only help with red blood cells. It will not help your brain absorb oxygen.

Good luck and be careful. Be sure to have a solid plan about who is making judgement decisions. The altitude deficits most prominently were regarding judgement.

My best to you.