This article discusses how an invasion could play out, and proposes that Taiwan could even win!
Notice how the staging areas shown in the map are well beyond Kinmen and Matsu
[Ian] Easton [a fellow at the Project 2049 Institute, in his book The Chinese Invasion Threat: Taiwan’s Defense and American Strategy in Asia] estimates that Taiwanese, American, and Japanese leaders will know that the PLA is preparing for a cross-strait war more than 60 days before hostilities begin. They will know for certain that an invasion will happen more than 30 days before the first missiles are fired. This will give the Taiwanese ample time to move much of their command and control infrastructure into hardened mountain tunnels, move their fleet out of vulnerable ports, detain suspected agents and intelligence operatives, litter the ocean with sea mines, disperse and camouflage army units across the country, put the economy on war footing, and distribute weapons to Taiwan’s 2.5 million reservists.
There are only 13 beaches on Taiwan’s western coast that the PLA could possibly land at. Each of these has already been prepared for a potential conflict. Long underground tunnels—complete with hardened, subterranean supply depots—crisscross the landing sites. The berm of each beach has been covered with razor-leaf plants. Chemical treatment plants are common in many beach towns—meaning that invaders must prepare for the clouds of toxic gas any indiscriminate saturation bombing on their part will release. This is how things stand in times of peace.
Be sure to read the part that imagines what a PLA soldier’s perspective might be. It starts with this:
To understand the real strength of these defenses, imagine them as a PLA grunt would experience them. Like most privates, he is a countryside boy from a poor province. He has been told his entire life that Taiwan has been totally and fatally eclipsed by Chinese power. He will be eager to put the separatists in their place. Yet events will not work out as he has imagined.