Hello Pullo,
Yes it’s possible, there is a little trick that sets a bottom padding on the iframe parent div. That padding is based on the aspect ratio of the iframe and it controls the scaling.
Here is a recent post with an example and a link to the method.
That was using flexbox but the same concept can be set up in a fluid width block div.
Have a look at the code example in that post and I’ll work on merging that concept into your example.