Tuning for hot august nights on E85

[turbo6man]

Hi I am going to take my car to hot august nights this weekend and have some fun. The tune at 200' altitude where I live is good and my Classic fast wideband control is between 0 and a max of taking away 7% at the 23psi boost. Ohh yea I am running 21.5 total timing in the higher boosts. My question is what is going to happen to my tune in Reno at 4500' elevation. Will my wideband be able to correct for the elevation. Also I have been told that cars like more timing at the higher elevation, but I am clueless about that. Any input will be appreciated. Please see sig for my engine specs.