A video file is just a video file. I don't know how big file wise video files are. But google does allow for file storage. I don't think they care what kind of file, they just have a limit on the amount of file space they give for free. So you get a google account, your wife gets a google account, then you have two places to store files. Google doesn't, to the best of my knowledge, delete files. Heck I have e-mails going back to the beginning of google.
If you run out of storage on google, you can always change your phone number and get another google account.
I think amazon also offers file storage, and a few other places they of course charge, but if it is just your files, it may be a reasonable fee.
Thanks for your reply!
I don't have a huge amount of video files anyway ... I just thought, maybe I could use a decentralized solution to save my videos, but it seems I have to choose a more conventional method as you suggested.