After a month and a half, lo and behold, I have the fix! Changing the network card, adapter, anthena and whatnot didn't solve the issue, but downgrading to an older driver did, weirdly. It's been running smoothly now for a full day, and seem to be stable. I will add a step by step tutorial for the rest of you.  1. Go to this page here and download the Intel(R) Dual Band Wireless-AC 7260 driver version 16.1.0.13,A02 2. Press Win + X and enter device managment 3. Open the Network adapter menue and uninstall the current wireless driver 4. Hold down shift as you restart the computer, from there, enter secure mode (It's important that you keep pressing in SHIFT as you restart) 5. Install the driver from step 1, but run it as admin. It will ask for an update or custom install, upgrade worked fine. 6. Restart the computer, enter your network key,  voila!  If this doesn't work for you, let me know. If it did, send a complaint to Dell on my behalf. I am furiouse with Dell for letting me wait over a month before they even cared to try anything, and for some strange reason they refused my 30 days return request, even though it was valid and a part of the deal. This is the first time in the five years I've used Dell that they didn't take me seriously, which in the end forced me to buy a second laptop for my studies. 
Hello I got my XPS 12 three days ago, and was sad to realize it did indeed have the known wireless issues. I will go into details as of what happens, as it is slightly different than what I've come across earlier.  When I start the laptop, it connects as intended, but after some use, it simply stops, yet, it still shows I am connected, and how strong the conection is. The only way to resolve this, is to disconect manualy and reconect. One out of ten times I may get a conection error, saying the adapter was unable to conect. Whenever I try to install larger things, the wireless stops faster, the less use, it stay connected for longer. Moody much? I have followed this link here, changed the settings as recomeneded, updated, tried different drivers, turn on and off, playd with the settings, alas, no change. I also tried getting in touche with the XPS premium support, but was directed to something called PWC (calling from northen scandinavia)? Needless to point out, they didn't pick up eighter of the times I called. I have the: Intel@ Dual band Wireless AC 7260 + Bluetooth 4.0 fully updated, I also recently ran windows updater, restarted my laptop several times to make sure it al intalled, and so on and so fort.  Keep in mind, I am not very steady on the computer settings, so keep it simple. And add colourfull pictures. Have a nice day!
XPS 12, unstable wireless, tried several fixes.