From this link I understand that my two options are:
- NTFS Quotas
- The "Limit profile size" policy setting
I prefer option (1) because I really want to limit the overall size of everyone's profile so a single user can't fill up the C:/ drive. However, if the quota is reached, I'm concerned I'd be unable to even log in as Administrator remotely to delete files or increase the quota. I don't think I can eg: limit "c:\documents and settings" except for "c:\documents and settings\administrator"
The alternative I can think of is applying an NTFS quota to each user's profile individually when the user is created - more work but at least I have the fine-grained control. This is what I'm currently considering unless you have a better idea?
In response to comments on the answers: this is a standalone TS environment with no other servers and all users use the TS exclusively.