Honestly, just setting up a scheduled email is likely the best option.... while you can create an "partner" user group in your admin panel, and then share that Workspace with them... I don't know if you can fully restrict access to them seeing other stuff in your suites.... I've not actually tried to do such a thing.. there's a lot of overhead involved....
This is one of the reasons why I am really looking forward to that feature they showed at Summit where you can share a Workspace with users who don't have accounts... you just need to share a link to the live report, maybe add a report level authentication, and let people access it without needing an account.
My Company's current policy is that we don't give access to partners... we will share reports with them, and add them to schedules for automated report emails... but we just don't give them access....