This question got me thinking - what types of activities are routinely performed when a probe is in a long transit (like Juno, for example)? What does the staffing typically look like? Does one (or a few) teams manage multiple spacecraft, or does each craft have it's own team?
The amount of man-hours required during the transit is probably very low. Is there even a need for 24-hour monitoring?
Juno was placed in hibernation (https://www.nasaspaceflight.com/2016/07/nasa-junos-arrival-jupiter/) during its trip so contact would have been sporadic.
New Horizons used a similar approach:
Heading into its first long hibernation cycle, New Horizons sent beacons once a month, requiring virtually no support for most of the time, decreasing time needed on the Deep Space Network and personnel at Mission Control. For two months each year, New Horizons was woken up to undergo a complete check of its systems and instruments.
The beacon was a very simple message: all ok/small problems/big problems. So NH would have needed one block of DSN time per month. IIRC a block of 8 hours is standard, maybe a smaller slice suffices for these beacons.
