Altitude capacity is an individualized response. If you can't train at altitude there are devices like AltoLab and altitude tents that provide some of the same training responses. Otherwise the rule of thumb is get there as close to your race as possible, and expect to really suffer on day three.
From a training perspective you'd want to push on aerobic recovery efforts. Go deep into 02 debt, then try to hang on at the biggest effort you can manage while still having the HR come down. Avoid going into the red if at all possible at altitude, it can take exponentially longer to recover for the same output at sea level. Don't bother looking at your power meter for help, everyone loses X percent power at Y altitude. PE is your friend.
I qualified for both the RR and TT's, and plan on going. See you there!