Load a fraction of the total data. For example 10%. Store the qvw uncompressed. Then see how big it is. Multiply it by 10 and you should have the size it will take up in memory. But that's only the data, not the memory needed for charts, calculations and user session. Perhaps this document helps: https://community.qlik.com/docs/DOC-7870
talk is cheap, supply exceeds demand
