This reminded me of something that happened a few years ago when working on SQL Server 2000. Same scenario. Following is what I did to resolve the issue:

a) Create a dummy folder (say "X") on a drive having ample space.

b) Created the same folder hierarchy (\X\Foldername) inside this folder as the path of the folder where tempdb was supposed to be located.

c) Mapped this newly created folder (X) as the drive (G-drive in this case).

On starting the SQL Server Service, it created the tempdb on this mapped G-drive which in turn was folder "\X\Foldername".