Solution 1:

I got round this with PSEXEC

On the server that currently stores your profiles bring up an administrative command prompt and run

PSEXEC /S "CMD.EXE"

This gets you into Session 0, effectively running as the local system account, at which point you have the ability to do what you wish with these accounts. I chose to use XCOPY

Xcopy . \newserver\share\ /E /I

You can use the /X switch to preserve the permissions. I chose to leave that off and separately script the permissions to allow access for server admins without having to mess about elevating Explorer or using explorer alternatives.

Once the profiles are across then its just a case of, as you say, pointing AD profiles at the new share\folder.