I've had some luck with the drm-next-4.7 on a somewhat older graphics card (Haswell), but only using 12.0-CURRENT. The last time I tried, with a snapshot from the 20th (of June), after pulling in the drm-next stuff, it wouldn't boot.
If you want to try it, I have a page I made when it worked, http://srobb.net/freebsdintel.html
It is for a different card, and as I said, it hasn't worked for me with the most recent snapshots. I _was_ able to install FreeBSD-11, then, using git, pull the drm-next stuff and that worked. However, when I did that, ports didn't work.
(I explain that briefly on the page. The few packages that I installed with pkg did work).