The best is to stay on the grounds either in dry or the limited hookup sites. Limited means low water pressure and 30 amp electric. When we lived in Albuquerque we still moved the rig to the grounds instead of fighting the traffic. Great to sit out in the early morning drinking coffee in your PJs with the balloons flying overhead.
As for the weather we had it all from very cold to very hot so just be prepared for most anything
. That's why we would get electric just in case we needed air. Heat isn't so crucial.
We also lived in Santa Fe for awhile and during the Balloon Fiesta the parks there raised their prices. Some more than others so you really need to check around. During means the weeks before and after also.
If you are military check Kirtland AFB they might have room for some of the time you're interested in. It's an hour drive to Santa Fe from Albuquerque on the freeway.
Nice area, enjoy.