Working with Direct Query and DAX calculated tables - refreshing on Power Bi Service

I am required to connect to existing Power BI datasets in another workspace. I then have DAX calculated tables based off these using SUMMARIZE. All works well in desktop - the issue is that refreshing is not supported in Power BI service.

This is the error:
Refresh is not supported for datasets with a calculated table or calculated column that depends on a table which references Analysis Services using DirectQuery

I've read in the documentation about this limitation. What workarounds are available for this?

I have attempted to import the data instead of using direct query by using SSAS data source however the dataset is too large to load and keeps timing out. (hundres of thousands of rows)

I need a way to work with these existing Power BI datasets and be able to add calculated columns and such based on them and still be able to schedule refresh.