Is this a scale issue or a frequency of co-location issue? e.g., What is the minimum number of people that must be collocated for an "office" to thrive? What is

Is this a scale issue or a frequency of co-location issue? e.g., What is the minimum number of people that must be collocated for an "office" to thrive? What is the minimum frequency that people must be together for them to collaboratively thrive?