As "New Meppel Cathedral" does not exist, no busyness level can be noted. The Grote Kerk in Meppel is generally not very busy outside of service hours.
Given that "New Meppel Cathedral" is a non-existent attraction, there is no 'busyness' level to report. If the question implicitly refers to the Grote Kerk in Meppel, a general assessment can be made.
The Grote Kerk in Meppel is generally not an overwhelmingly busy attraction, especially outside of church service times or special events. It typically draws a steady, moderate stream of visitors, including locals and tourists interested in history and architecture. Peak times might occur during summer tourist season, local festivals, or when specific events like concerts are held. Weekdays generally see fewer visitors than weekends. For a quiet visit, late mornings or early afternoons on a weekday are usually ideal. During major religious holidays, attendance for services will be high, but sightseeing during these times is usually discouraged by local congregations.