I upgraded to iOS 9.1 on iPad mini and now can't connect to wifi. i've restored and reset, nothing works.

Try restoring with iTunes.

Use iTunes to restore your iPhone, iPad, or iPod to factory settings - Apple Support

The only other idea that I have is to make an appointment at an Apple Store and let them take a look. You might have developed a hardware problem or it could be something that they can fix by using more sophisticated ways to restore.

I have the same problem. WIFI connectivity suddenly went out yesterday morning for both my iPad and iPhone AFTER updating to the latest iOS. I have also tried every single suggestion and NOTHING works.

I've sent 4 requests for customer support. No response at all.

Can't find any article or story where Apple as acknowledged and/or solved this problem.

m7harris wrote:

I've sent 4 requests for customer support. No response at all.

Sent the requests to where? Did you email support? Make an appointment at an Apple Store?

I used the customer support icons that require you to select from several other icons indicating what might be wrong with the device. An email was sent to the device, I clicked on it. A diagnostic app began to run on the device. I agree to a privacy clause and the diagnostic apparently ran, but there was no indication that a solution or customer service response would happen. I did this to both iPhone and iPad twice. No email folllow or response. No indication that any data was sent or that anyone was going to respond.

I am making an appointment to visit a "Genius" to see if they can't Google the problem better than me.

Seems to me that if hundreds of people are having the exact same problem, there would be some kind of announcement or statement addressing. There are multiple reports going back several months of individuals losing WIFI connectivity after the latest iOS update. However, there aren't many solutions to be found.