I have Exchange 2007 and I'm going to migrate it to Office 365. In the end I want the users in the on premises AD to be the same on the Office 365 so that when I need to create a new user or reset someones password I only need to do it on the on premises AD and have at the same time SSO. There are about 20 users in the exchange server so I want to do it during the weekend in one batch only. What is the better option? Stage or cutover migration? Which is more complex?