so far for me the best thing I have done with my dell is use a mini usb adapter via OTG (dell sells one that allows you to charge and have the slot) not the best solution but for times when I know I'm gonna use the internet more on that device. Light browsing I don't run into that issue it is more common when I put the wifi under a heavier load downloading high res video or files it likes to conk out. Usually restarting the device for me has worked to get the driver back. if you are wanting to have a stable connection then that would be the easiest solution as this problem hasn't been resolved and does not appear that it will be any time soon.
There is an un-used usb slot on the motherboard and enough space inside to fit another wifi adapter so that may be the solution if you don't mind doing some soldering and a little cutting down on the back plate to get the tablet back together again. There are quite a few tutorials around of people tapping into that if your curious.
After upgrading to Windows 10, tablet couldn't find my wifi network. I had to go into Windows settings and type in the net address info for the network. It's worked okay since then.
I had no WiFi connection or options on my Dell Venue 11 Pro, but after reading your post and realising my tablet had been left in standby for a few days, I tried your fix.
I now have fixed my issue thanks to you! 🙂