Before you try to migrate your data, you need to make changes and potentially change subscriptions.
Because of the relatively high cost of SSD storage, when buying a new Mac you might choose to pick a smaller-capacity drive than in a Mac you’re replacing. That might be to reduce the overall expense or to spend your budget on more RAM or a faster processor. Apple still offers laptops with 256GB SSDs, and that seems a little snug if you have digital downloads or ripped music and take even a modest amount of photos and videos.
iCloud is a solution for offloading on-device storage and offers a kind of loose backup of that material, too. In the US, you can upgrade iCloud storage from the included 5GB to 200GB for $2.99 per month and 2TB for $9.99 per month.
Here’s a strategy for migration, if you’re comfortable with many of your files having the only copy living in iCloud.
Read more at MacWorld.com