The error you have posted is from a SLE that only uses the binding to the main WeeWX database, it does not use ws_binding, so I am confident the error has nothing to do with ws_binding or the lack thereof. Nor is it likely an issue with incompatibility with the Seasons skin. I suspect the issue is more likely some incompatibility between the SLE concerned, MonthStats, and the wee_reports environment. Whilst weewx-saratoga was put together in 2021 much of the code, in particular the SLEs, is some eight or more years old and whilst updated for various WeeWX changes over the years it likely has some issues when run using wee_reports. I will try to find time to have a look at the problem, though unless it is a quick fix it will likely be some time before I have time to track down and fix the error.
Not sure what you are trying to achieve, though judging by your questions regarding iterating over months/years, I gather you are trying to develop some sort of historical monthly aggregate based reporting. If that is the case, and if you are going to continue to use the weewx-saratoga SLEs, I would suggest you just load those SLEs that are required (I suspect that you probably just want the MonthStats SLE). You might find running a separate WeeWX development install with a short (1-2 minute) archive interval may compensate for being unable to use wee_reports with this SLE.
Gary