Migrating to a new iPhone while in the middle of syncing thousands of photos to iCloud Photos
I ran out of space on my 256 GB iPhone, so I decided to start using iCloud Photos and the “optimize storage” setting to free up a bunch of space on my phone. It’s a lot of data though, and after 4 days I only have uploaded 11% of the photos. I’m hoping to pick up the iPhone 11 Pro soon, but I have a feeling this upload is going to take at least another week or two, and I have to send my carrier my old iPhone as a trade in. So my question is: what is the best way to proceed without losing any photos or having to wait 2 weeks to use the new phone?
Here’s what I think my options are, but I don’t even know what will actually work (and neither does Apple Support):
1.) pause the sync and then use the WiFi/tethered 12.4 “Migrate to new iPhone”feature to restore to the new phone and reset the old phone, and restart the sync on the new phone,
2.) pause the sync, then use the “Migrate to new iPhone” feature to restore to the new phone BUT keep the old phone active and at home on WiFi to continue uploading to iCloud Photos, or
3.) cancel the iCloud Photos upload on the old phone, then use the “Migrate” feature to copy everything to the new phone, and then start the sync over from the new phone
I’m thinking I should do one of those, but my questions are:
For 1.) would there be a problem with the unsynced photos that will prevent me from restoring all the unsynced photos?
For 2.) would there be a problem with two different devices trying to upload the same photos? If iCloud Photos is on for both devices, won’t they both be trying to upload the same photos to the cloud?
For 3.) when I cancel the iCloud Photos upload, what happens to the photos that were already uploaded? Does my phone now redownload them? Or are they stuck in the cloud without a way to get them back until re-enable iCloud Photos?
Also for 3.) can I just fix it by changing “optimize storage” to “Save Originals?” Then maybe it will re-download all those photos, and I can then do the transfer to the new phone, and resume the iCloud Photo upload.
Sorry for the long winded post and thanks for your help!