Create a users file (i.e.
users.txt) for mapping SVN users to GIT:user1 = First Last Name <email@address.com>
user2 = First Last Name <email@address.com>
...
SVN will stop if it finds a missing SVN user not in the file. But after that you can update the file and pick-up where you left off.
Now pull the SVN data from the repo:
git svn clone --stdlayout --no-metadata -A users.txt svn://hostname/path dest_dir-tmp
