Unable to download a 2 hour long video from iPhone 12 to 2019 iMac with Monterey

Hi,

I recorded a relative telling family stories on my iPhone12 and the video lasted 2 hours. I am home and have been unable to download the video from the phone. I've tried to transfer directly via USB to Photos, and it doesn't even show up on the phone, and I've also tried sending it to my computer via Airdrop. The phone tells me it's preparing but the phone goes to sleep after 15+ munites and never finishes, and never starts the download. Are there any tricks to getting a huge video file off the phone?

Thanks in advance,

Melissa