I am using both Pro tools and Cubase.
I can confirm that it is possible to do a batch export of song length synced stems in Cubase and then import those into individual stereo tracks in Pro tools. You can then proceed to work with those stems in any way you desire with plugins, effects etc… After you have finished doing what you wish then you can either render that entire song again in protools therefore creating identical song length stems for every part, or; you could save the entire session as a new session and then pop along to your big studio with those files.
IMHO-This would be your best option.
The gentlemen that stated a rewire would be a pointless and altogether unrequired headache I believe is completely correct in his assertion.
Good luck
Basil Simon