As described on GC a PQ can contain a set of caches (up to 1000) that can be selected. Region selection is a bit limited for me (you can select a country, sometimes a state/community, or a circular area around a given point) but filter options make this quite flexible, in particular when selecting only a specific date range. The date range partitioning is actually supported by PGC as well to 'chop up' a specific area into groups that are within the PQ limits. The PQ can then be downloaded in compressed (.zip) format and handled further.