How to merge most but not all photos from old laptop to new laptop?

In 2019 I did a clean install on my iPhone and continued to take photos and transfer them to my OLD laptop. From 2016 to today I have about 150 GB there.

I just got a new laptop and have transferred all the photos from my phone to it, but there are 100+ GB of photos on my old laptop that I want to move there as well.

I suppose I will have to move them first to a hard drive first (I don't use iCloud).

Question: I've never imported from a drive into Photos much less tried to merge them with existing photos. Is there a way I can do this transfer so that all the pre-2019 and post-2019 end up together again on my NEW laptop just like they are on my OLD laptop? I would like to just specify an ending date when either saving from OLD to the intermediate hard drive or when importing to NEW laptop

note: I ran out of space on OLD so there is a big chunk of photos in my phone that never made it there, otherwise I could just do them all at once.

Solution 1:

This might sound crazy, but AirDrop might be the easiest solution for your use case.

50000 photos might sound like a lot but local Wi-Fi transfers can be even faster than hard-drive/USB drive copying on modern routers.

I just tested sending 100 photos from my wife's laptop to mine:

1. The transfer finished in a few seconds
2. I was presented with an import screen in Photos where I could choose what to import and where
3. All photos were imported in their original chronological order and in the same folders they were on my wife's laptop

On the OLD laptop

On the NEW laptop