Is it possible to log onto the remote CVS server and download all the source code to my pc using CVS?
Yes, this is possible. In fact it is what CVS was designed for. The thing is, you need to have permission to check out the source code from the CVS server. Not all allow anonymous access. So findout from the server if you are allowed to checkout code, and get a username/passwd if necessary.
Now check out 'man csv' or this site:
for the command to actually checkout the source.