FYI When I reset my 920 the entire current list of apps and email accounts all got restored automatically. The only two things I had to do manually were to enter the passwords for my email accounts and re-arrange the tiles on my home screen. Assuming this also works when migrating from one to another, just make sure:
1. You perform a backup (to Skydrive) just prior to decommissioning your 920. This is under settings and only the categories you select (app list + settings, text messages, photos) will get backed up and restored properly. In my case all were selected and all got restored.
2. You have an active data plan and decent cell signal / connection when turning on the 1020 for the first time. This is needed because you will not have WiFi connectivity yet.
3. Log in with your Microsoft account the very first time you get asked.
4. Choose "yes" when you first get asked whether or not you want automatic backup enabled. You need to say yes here in order to get the restore option next, which could be a bit confusing / misleading. If you say no then you will not get the option to restore even if you enable backup later, so you really only have one shot at it (unless you reset the phone and try again). Once I completed the setup I connected to WiFi so the rest of my photos/content to restore didn't use up my cellular data.
I found that I had to meet every one of the above criteria but YMMV.