Copy existing Budget to another existing budget?

I am looking for help/advise on an issue brought up by the accounts department. 
Oracle 12.1.3

1)      Divisional accountants enter their budget data into the so called 'Draft Budgets' (manually by a range of users)
2)      then the Group Accountant reconciles the Draft budget and any further changes needed are done by the divisional accountants
3)      When the draft budgets are agreed and finalized, the Group accountant then downloads the DFT BUDGET using the budget wizzard
4)      then uploads its details back to the actual BUDGET,   using the actual Budget  specific ADI template.

The issue with this process is that the budgets consists of 18-20,000 lines for each org. and both creating the new templates, but specially the upload back into the system for such volume takes very long. the users are looking to see if there's a way to bypass having to upload all that info each time.