Up/downloading big crm documents using script - Script is taking too much memory

I'm trying to up- and downloading documents using crm-script in Customer Portal. The files are big. 50-150 MB. I'm using "printBinary" when I'm downloading. And

"decodeBase64AsStream(base64)" and "documentAgent.SetDocumentStream(....)" for creating document.

When it's above 50 MB I get " Script is taking too much memory" Is it possible to change the memory limit for a given tentant Id?