If I were you I would:
1. make one master folder on say my desk top.
2. then subdivide the master folder down into one folder for each song you want to work on
3. then for each song, export each individual track of that song as a 24 bit, 44.1 wav file (and if you have the room an MP3 at say 196 or even 320 bps) into its proper folder.
4. Finally I would save this master folder with all the sub folders that contain each individual track for each song on to say a 64 gig flash drive, a Re Writable DVD and if you have it a portable HD. Triple security...If you do the DVD bring extra DVD's with you....BE PREPARED
this way you have each track as a Wav and an MP3. (any studio worth their salt will have the ability to import a 24 bit, 44.1 Wav file or anMP3 file. If not then I would rethink the whole deal........seriously!!!
You will have them all organized by individual songs
All organized inside a master folder.
this way when you go to save the new tracks you will save them in their individual song folders and when you get home all you will need to do is import the new trackes into Sonar and away you go....
Again the biggest thing is BE PREPARED in case they are not....if you are prepared then the likely hood of a disaster is minimized....
If you have any midi or soft synth parts then before you start to export the individual tracks I would freeze the synth parts and export them as audio as well......24 bit, 44.1 Wav files......just like everything else.....
Clifford