When working with large files via WebDAV, you may encounter errors during upload/download.  These errors are controlled by Windows on each individual PC. 

Windows defaults the limit of downloads to 50MB and uploads to less than 30 minutes.  Users can adjust these settings to increase the size and/or timeout as needed.

These settings are outlined at the Microsoft Knowledge Base article linked below.  Note there are two separate settings, one to handle uploads and the other to handle download.

Microsoft KB 2668751