When shipping living plants, the #1 enemy is rot, not desiccation. I've seen far too many shipments where an excess of caution led to the plants being packed far too damp and arriving at the other end rotten messes.
Remember that in the late 1700's when William Bartram was shipping American plants by sea to Peter Collinson in the UK, the plants were packed in living moss and most arrived at their destination intact after a three-month journey. (I should add that Bartram's reference to sending "roots" suggests that he was shipping dormant plants.)
In these our modern times, another hazard is overheating in a delivery truck parked in bright sun but here too moss may insulate the plants from the worst effects.
Three days is not a lengthy journey, however, so your gifts to your father have an excellent chance of reaching him in good condition.
Remember when packing that parcels may be thrown, turned upside down, shaken, and otherwise mistreated while in transit.