I've had the same problem. I'm on a Dell 7520 laptop with the Intel Wireless N 2230, and didn't have any problems to begin with. Last summer the connection started to drop and got gradually worse as I updated to Windows 8.1 from 8. Eventually the problem got so bad that I decided to restore the laptop to it's original factory settings, and then updated over the next week before installing 8.1 again. The problem continued, with drops occurring at one point within minutes.
I've come to the conclusion that the problem is both the newer drivers and Windows 8.1.
I've restored the laptop a number of times now and found that the original setup works better than the latest software with no drops before updating. My current setup is Windows 8 with the earliest driver 15.5.6.48 dated 04/10/2012. I've turned off automatic updates so that it notifies me of them, but I can vet them before carrying them out, so everything else is updated. I've had no drops for a week now with this setup, as I had before a few times. I'll keep you updated as time goes by.
Windows 8.1 will NOT let me install the earlier drivers, as it assumes I'm using a v.16 (?) Intel card so it's off limits for me right now. Hopefully Intel is examining the older driver and comparing it with the new ones so they can find out what changes have been made.
As earlier said on this thread, the Microsoft drivers do seem to improve connectivity from my experience, but this setup seems to work for me.