We watched it from Frontierland as we walked toward Liberty Square and stopped at Liberty Square. It is very close to the fireworks, but the angle is "warped." It is clearly better from Main Street, but they can still be enjoyed from a less crowded area. We noticed a mist during the fireworks and wondered if Disney sends a water mist out to counter the ash that flies down. You will catch little or no view of Tinkerbell from this location.
the first time we saw it in Dec we watched from there - I think we were on some bridge or right along the water. You could see it well, but the next night we went back to watch it from main street and that was spectacular!
I would cut over through Adventureland and then go on the path in front of Crystal Palace. Then there is a path from Crystal Palace to Main Street. We watched Wishes from there and had a great view, not as crowded as Main Street itself. If you want to leave when it's over, cut through Casey's, you can go through the stores all the way up to Town Square.
We watched Spectro from Frontierland and then shuffled to Liberty Square to watch the fireworks. the view wasn't as perhaps as grand as on Main St., and we probably missed some of the effects, but I didn't care----it was deserted in Liberty Square and it was great not having to fight any crowds. We grabbed and popcorn and oohed and aahed with a small handful of folks.