I can't respond to the 'pro Airstream travelers' bit, but frozen blocks and a battery-powered fan will both help cool the fridge. I would recommend plugging the fridge in 24 hours prior to you planning to use it, and stocking it with cold goods as soon as it's cold enough. Ammonia-absorption fridges do not cool quickly. They generally take six to eight hours (or longer depending on the size of the fridge) to cool to operating temp.
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"