We are currently considering using flickr for our website gallery and to share the monthly photos with the group at meetings. This should simplify things for everyone, more of this to be discussed soon. However, as mentioned in his latest post, Cliff requires the full resolution versions of some of your photos. I suggest you use WeTransfer ( https://www.wetransfer.com/ ).
This website allows you to transfer large (upto 2 Gb) files from one email to another. You fill in the details on the page and then upload the files. Cliff will get an email and he will be able to download the files. You do not need to sign up for the paid service 'WeTransfer plus' if you have more than 2 Gb to send in multiple files, just send them in 2 batches.
You may get asked about cookies. I can reassure you that I have been using this site for years and have had no issues with spam etc. (It does use Google analytics I believe, but then so does almost every site these days and no data provided through that is personally connected to you.)
Hope this makes things easier,