We have done two NYE trips and are going again this year.
On our first we stayed at Kidani Village. I had read EVERYTHING about going at that time of year and I followed vlog/blog/and disboard advice. Apparently so did everyone else because it was pure insanity. We waited for the bus to go to Epcot on NYE for over an hour, and then we got stuck in traffic on the bus for over two hours. Just between Kidani and Epcot. The roads were a parking lot, people were literally turning around in the grassy median of the road. While on the bus, we watched a woman get out of her car and use the bathroom behind a monorail support structure. (yes, seriously)
That trip was a huge learning experience, and the following year we did NYE again but at the Polynesian. We're booked at the Poly for our upcoming NYE trip too.
I would stay somewhere with only bus transportation on NYE again, but ONLY because I now know when not to try to travel where and at what time of day. Getting TO a park midday is normally the issue, getting back to your resort midday isn't that bad. So if you go out at rope drop traffic is pretty normal. It gets bad around noonish and stays that way for several hours.
Based on my experience, I would start being brave enough to venture back to a park around 6pm, because a lot of people leave after the first set of fireworks at Epcot and MK, so it's a little easier then to get somewhere. No matter where you stay, leaving at midnight on any kind of transportation is crazy, so we prefer somewhere with options (bus, boat, monorail, skyliner)
Our new favorite way to celebrate NYE is to go to a park early, and get back to the resort around 3pm, hang around the pool, go to dinner, and watch the fireworks from a resort. So much less stressful in my opinion.
Both of those trip reports are in my signature if you want to check them out and get an idea of what we experienced. After our first NYE I said never again, but then booked again for the following year
But once you know what to expect, you can adjust, and our second time was one of our favorite trips ever. Hoping this year is just as awesome.
Have fun!!