

Well, you won’t like it. If you have very fast internet and a managed downloader, then you may be able to get all of the files. Google seems to throttle the speeds to make large takeouts almost impossible to download in the limited time allowed.
For this size of download, your best option is to get a subscription to a compatible service (Dropbox, etc.) To transfer the files, which will happen much more quickly than downloading yourself. Then download the files from that service at your leisure, and then cancel the service.
It’s pretty backwards, but it’s really the best option for large takeouts (over 5 gigs or so).
Also, you will need to do some preprocessing of your files before importing to immich. Something like this to fix the metadata. I can’t remember which one I used, because there are a few out there.