I am currently migrating all of my Multisite installs:
Now that you have your snapshot ready, install a brand new WordPress site (or Multisite install) on your new server. This also includes all instances of where you would like your site to be moved whether you would like to migrate a site within a network or adding a site to a network.
Does this mean that I should create all of the subdomains in the new install first before I migrate?
( I have not had success yet as I get an "Error establishing a database connection" error: https://premium.wpmudev.org/forums/topic/migrating-multisite-with-snapshot-pro#post-1232603)