The SharePoint Online service administrator can set the storage limits for site collections and sites created by users. The minimum storage allocated to a new site collection is 24 megabytes (MB). The maximum storage available for any site collection is up to 100 gigabytes (GB).
The maximum SharePoint Online storage available to a single company’s tenancy is up to 5 terabytes (TB).
File upload limit: 250 megabytes (MB) per file.
If your files are over 100G, you cannot upload the files to a single site collection.
Be aware that, the Workspace’s max size is 2GB and the total number of files you can store across all your SharePoint workspaces is approximately 10,000.
Please refer to the links below:
http://support.microsoft.com/kb/916412
Except using SharePoint Workspace, you can choose your document library in your team site, then in the ribbon, under “Library ”area, click “Open with Explorer”. A explorer windows will pop up. Thus, you can drag your files to the explorer windows.