can I do this more than once
Can I migrate from old to new mac more than once?
Sure, that is the idea, move from one machine to you next machine seamlessly.
Since OS X Panther 10.3 and 5 five MBP I have never had an issue using the Setup Assistant to move my user th the next machine.
Set up your new Mac - Apple Support
How to use Time Machine to back up or restore your Mac: https://support.apple.com/en-us/HT201250