I seem to have fixed the problem at last using the suggested solution to downgrade to the 6.x driver (before it was disconnecting every few seconds and now it's been holding a super weak signal for a while without disconnecting once). Paradoxically I found the Broadcom driver available on the Lenovo site (it has been removed from the Dell site as per my previous post!) - here a link for anyone still trying to play IT Technician on Dell's behalf: support.lenovo.com/.../ds103679
I have been having problems with 2 issues, the WiFi and speakers. Problems with both of these areas come and go, but it is frustrating nonetheless as I purchased this laptop only a few weeks ago!  1)WiFi I had issues with the laptop in which the WiFi would disconnect after using it for some time, usually around an hour's time. The wifi icon would show as limited access with no internet access and disabling/enabling, airplane mode, and all the other methods described on these forums would not allow the laptop to neither connect nor find my wifi network. Restarting the computer would solve this problem. It got really frustrating so I exchanged it for a new one at the Microsoft Store. With the exchanged new laptop, the exact same wifi issues would arise. Every device that is connected to the network was not having any connectivity issues and my router was working fine whenever the first and second laptops had the wifi issues. I then called Dell Support and i was instructed to install the wifi and bluetooth drivers from the Dell website, but the same issues with wifi going into the limited/no internet access and not being able to see the network would occur again from sleep mode/using it for some time. I found a thread in which someone unchecked the box that said something along the lines of "turn off ____ device to save power" which I'm assuming was a device related to the wireless card. This seemed to resolve the issue for about 2 weeks up to until a few days ago when the problem would start up again. The wifi icon would go into the limited status with a no internet access caption and the disabling/enabling and airplane mode tricks would not do anything. Going into the network and sharing center once I disabled the adapter, i would try to right click and enable again but the icon would stay as disabled no matter how many times i clicked enable. Restarting the computer is the only way the laptop seems to find the network again. Everything is updated as of this post. 2) Speakers The second issue is the speakers. Everything works fine except for a few times when I have used Cortana. when I click on the mic icon to speak and Cortana speaks back, there is a buzz along with the voice. Likewise, sometimes it Cortana would say that it's not working and to try again later. These issues are really frustrating(especially the WiFi issues) and I really need some help with these problems as the offshore Dell Technicians I have encountered are very rigid and robot-like and they do not seem too helpful other than on basic issues. I love this computer but if these problems keep occurring, I feel it would be better to just return it as it is still in the 30 day period.
Dell XPS 13 WiFi and Internal Speaker Issues