Upgrade Portals from V5 to V7 (CRM2011 to CRM365)

I'm starting an upgrade in an on-premise deployment with the following source versions:

-CRM 2011 UR18
-ADX Studio Portals 5.0.18.0

The destination on-premise deployment will be:

-CRM 365
-ADX Studio 7 (latest release that supports CRM 365)

For the CRM upgrades, I'll be building separate CRM2013, CRM2015 and CRM2016/365 environments to handle each CRM upgrade.  Although there are multiple steps, it's fairly straightforward and I've done this many time before.

However, upgrading ADXStudio Portals is new territory and I'd like to confirm where I run the related upgrade steps.  Do I do upgrade this product during the same steps I'm upgrading CRM (ie CRM2013, CRM2015, CRM2016/365) or do I wait until I have my final CRM365 environment and then install/upgrade Portals?

Any help, best practice hints or links to articles is greatly appreciated.