There could be a major bug in one of the mods and your the first to find it. Happen to me with a mod from here i think it was RSRD can't remeber as it was a while ago, everything was working okay then one day my FPS just plummeted to practically zero - turned out the mod would spawn to many convoys must of been in the 100's in the same area or whenever you reach that part in the game it triggered
causing any system no matter how uber to crash.
If the problem is happening in the same area each time then its likely a bug in the mod and i would let the developer know about it so he can add a fix.