webi report refresh

There is a webi report which needs much resource to refresh it and groups of users: Group1, Group2, Group3 etc.
Every group should view only data of its own company.
(In real there are a hundred of reports and about 20 groups of users.)

The task is to refresh the report at night.

I have considered 2 ways.

1. To copy the report in matching to groups Folder1, Folder2 and Folder3 and to schedule them for specified groups.
   It works fine but in this case number of reports and schedule jobs multiplies by number of groups.
   And you have to repeat many times coping report in folders and rescheduling it after a report modification.
2. Publications.
   Publications fit to task almost completely.
   But publications do not have BI folder destinations.
   An Inbox destination does not have a structure and users will have troubles to search needed reports in a long list of inbox.

Is there other way to solve the problem or use considered ways more efficiently?

Thanks for any help.