You are welcome :-) It is the type of information I wish I had when I did this project. It is worth doing the google takeout of your photos anyway even if you just keep them as a backup to a backup.
Fixing the file dates is not as daunting as it might look. It is actually very fast.
I used google takeout to download ALL of my google data since I am actively trying to de-google. But you can just select to download google photos only for now. immich has a nice import utility. I have not used any of the others.
WARNING: google has removed the file modified date and the file create date so when you extract the files from the takeout zip file, they will show as being created and modified on the date you extract them. This will cause immich to import all of your photos on the same date instead of importing them into the date they were taken, which is less than ideal.
Solution:
Download and install exiftool
Open a command line and run the following commands from the directory where you installed exiftool:
To change image files:
exiftool "-filemodifydate<datetimeoriginal" "-filecreatedate<datetimeoriginal" "drive letter:\path to\your\photos"
To change MP4 files:
exiftool "-filemodifydate<createdate" "-filecreatedate<createdate" "drive letter:\path to\your\photos"
To change AVI files:
exiftool "-filemodifydate<createdate" "-filecreatedate<createdate" "-filemodifydate<datetimeoriginal" "-filecreatedate<datetimeoriginal" "drive letter:\path to\your\photos\*.avi"
If the files are not updating you might need to verify the tags your files have:
exiftool -time:all "drive letter:\path to\your\photos\some.JPG"
This will list the tags on the file and you can update the commands above with the appropriate tags for your situation.
Obviously keep your takeout zip file as a backup and test these commands out on a few test images, but I did these commands to update 20 years worth of google images.
I do not know which provider would be best to host as I am self-hosting immich. I am backing up to external drives and also to Backblaze B2.
If you need any assistance just send me a message and I will help if I can. :-)