What exactly do you mean by a "cold storage" wallet? Armory just creates wallets... or you can create a watching-only copy by clicking on the "Create Watching-Only copy" at 'Step 5' of the wallet creation wizard:
or by using the "Delete Private Keys" option (Wallet Properties -> Delete/remove wallet):
"Cold Storage" is not a special wallet type, per se... it's simply a version of Armory running on an offline, air-gapped PC. It's being "offline" that makes it "cold storage". So, if you have the paper backup for your "cold storage" wallet, you can simply restore it on any copy of Armory (offline or online). You certainly don't need to restore it on an offline machine and then transfer the wallet file to an online machine... you can just restore it directly on an online machine.
You can easily test this... just create a new "dummy" wallet for your "cold storage" machine... then simply restore that dummy on your online machine using the root key backup. You'll see it creates the same wallet.
Or am I misunderstanding what you're attempting to do... and you want to be able to restore your full cold storage setup as it currently is?
In which case, restore on the offline machine, create the watching-only copy during wallet creation... and then transfer the "watching-only" copy to your online machine.