How to download photos in mass from an iphone/ipad from iCloud...

I do not imagine I am the first to hit this road block...
This post assumes one has no Windows or Mac computer.

How do you move photos from your iphone/ipad to your Ubuntu computer?
All ideas welcome!

Background info:
You can use Firefox and go to iCloud.com:
...But can you select more than one photo at a time?
I could not using old accustomed ways.

You can plug your iphone/ipad into the USB port of a Ubuntu laptop:
I found clicking on the iPad that the folder was empty - as in nothing at all on the iPad?

I could plug my iphone/ipad into my wifes Ubuntu laptop:
I found that out of the 14,500 photos I have only 250 or so were in the folders?

My wife can plug her iPhone into her Ubuntu laptop via USB:
My wife who does not store photos in the cloud can move all of hers to her laptop.

Details:
Ubuntu 16.10 and Firefox 53.
IPad Pro.
IPhone SEs.
14,500 photos - 41GB.
At the time of this writing every everything was current and upto date.
I need 41gb of storage on either IDevice to not use the cloud and download all my photos - I don't have it.