Okay so the most requested feature (Apart from selecting multiple provinces) is probably multiplayer.
I'm not sure if this game is even able to connect to the internet. Regardless we've seen single player games such as Blade and Sorcery become multiplayer, so I believe this game has a shot too.
The main argument against adding multiplayer is the game will take forever. The thing is this issue can be easily overcome by doing a system where its everybody's turn at once. Lets say theres a turn timer of 10 seconds, everyone cast their orders then when time is up or they hit "Ready" button when done. The small modern day map that way you dont have to manage many provinces and waste time. The first turn may be 20 seconds to get prepared and sync everyones game.
Once a player is finished with their actions the "Next Turn" button will be replaced with "Ready".
With a system like this you can fit a lot of people in one server without any problems.