What will happen if both players have no money but Terran can fly base in map's edge?

According the liquipedia stalemate detection has been in SC2 ever since patch 1.2:

A stalemate occurs when all players are unable to complete any of the following actions:

• Generate income
• Produce a unit
• Construct a building
• Research an upgrade
• Destroy an enemy building.

After three (in-game) minutes, if no player has completed any of these actions, the game issues a final three minute warning. If these final three minutes elapse without a player completing any of these actions, the game ends in a draw for all remaining players. If a player completes any of these actions, the timer resets and play continues normally.

If you think its unfair for some reason that the terran can force a draw in this situation even if you have a lot of ground units... All's fair in love and war