Hope This Helps!
Here are some suggestions I thought of: (Hope they'll help)
Highly Recommended
1. Use
Vexorian's Map Optimizer to protect and compress the map.
2. Like what thekebecer suggested, read tutorials like
this (Scroll round the bottom of it) to help you.
3. Sign this
petition through this
thread. (If you have a Battle.Net account)
4. Create a program, like how people made
Project WarSoc before, to help give a new platform for the map to run. (This can be quite time consuming)
5. Find out the best and least space consuming way to write certain triggers, therefore helping reduce file size and still doing what it should do. (You can get some help if you want)
6. Remove leaks by checking it with the
Leak Checker.
7. Pray for a miracle to happen.
Slightly Recommended
1. Remove access custom models/sounds/imports of any kind that aren't necessary.
2. Get a standard or low quality loading screen.
3. Edit the terrain to reduce it's quality and make it less space consuming.
4. Remove some map boundaries to take less space.
5. Delete some triggers that will not affect the game much.
6. Split your map into several 'parts' by creating different maps meant for different areas, for example. (You could use loading and saving for this even if it's not an RPG)
Not Recommended
1. Remake the map into a 'miniature' version of it.
2. You could try configuring it to be played on a Single Player based platform.
3. Transfer your map to Starcraft II. (I personally don't support this, due to the fact that I'm a die-hard Warcraft III supporter)
4. Hack into Blizzard's multiplayer system to configure it to allow maps of a higher file setting. (I don't support this either as it's illegal, do it at your own risk)
5. Drop the project and start on a new one. (It'll waste your previous efforts, though)