Twitter bootstrap3: HTML5, non-cross-domain iframe scale width and height

Twitter bootstrap3: HTML5, non-cross-domain iframe scale width and height

Dear Elders of the Internet.
I know this has been asked many times before, but please read on.
In twitter bootstrap 3, I am trying to get an iframe to fill out a div ID.
I have scoured the internet and SO extensively, and tried every single
thing I have come across with no luck.
Here is the poop:
I need to load an html-page in a narrow div ID. It is not cross-domain; I
have control over both.
I need to be able to style the content inside the iframe. Can I do that
from "master" page (i.e the target page), or do I need to do that in the
"incoming page", i.e. the iframe content html?
the iframe must be flexible: the height and width (width because of
responsive design) need to expand according to content.
I am desperate, and wondering if Bootstrap3 is overriding something?
I have tried a desperate amount of css alteration in combination with the
long list of css and js-solutions listed below.
...and please do not shout at me.. I am doing my best.
Any pointers would be greatly appreciated.
Here are a bunch of things (not all) I have tried :-S
Twitter Bootstrap iFrame usage?
What's the correct way to size an iframe in a Twitter bootstrap fluid layout?
http://bootply.com/search?kw=iframe
get and set iframe content height auto resize dynamically easy solution
expanding tutorial (not a question but an answer)
Make Iframe to fit 100% of container's remaining height
cross-domain iframe resizer?
to fit iframe to its content height