It might be that the question could have been more helpfully precise.
Making the assumption that it is based on there being no streaming coverage the first question is what the source material is going to be.
That forces another assumption, namely that one wants the media stored on other than DVD
Next assumption, you are prepared to break the Digital Rights Management (DRM) on those discs. Unless, of course, an unending diet of home movies is what grabs you.
If so, your call and I am not encouraging you, you will need to familiarise yourself with something like Handbrake and the add in file needed.
Next assumption, you really, really are serious about being able to watch what you have saved using the minimum amount of power if need be.
If you are, then use or buy an Android phone
and throw away/sell anything from Apple that you have. Why? Two reasons. First, (Cr) Apple phones do not support removable Micro SD cards. So you are struck with the generally miserable and over priced internal storage
. Second, the over priced phones only talk to equally over priced display kit. Android talks directly with a dirt cheap USB to HDMI cable to Screen. Or wirelessly through a number of protocols.
Now, if you go with this suggestion you will have one device which uses very little current
and can take any number of interchangeable cards. If you want to share to a bigger screen you can.
What's more, because you will have the phone
with you the data will be available to use in lots of places. For example, I use the phone at home, second home and on the boat. All with different output configurations. None of which have cost more than peanuts.
One tip, if you do go this route
then go for a phone with USB-C rather than Micro USB. You will future proof and get much better data handling.