Is there any historical data that could be converted from dynamic
formulas to static text? For instance, if a particular number is the
result of a formula and that number will never change because it occurs
in the past, copy that cell and paste it over itself as a value.

Additionally, if historical data needs to be a formula but is relevant
only to a particular timeframe, you could save that timeframe as a
separate file and refer to it as needed, instead of maintaining it in
the current file. That would reduce the current files demand for
resources.

Dave O