What if Germany fights it out in 1918?

Yes, but that is only a map of the north east part of france. As has been said, at their greatest exent Germany only occupied a tiny corner of France, unlike that in WWII>

Here is a wiki article on the reparations:

I don’t want to join this argument. Argue with the map.

I wouldn’t want to mow it.

Especially as many of the most important French villes martyres, such as Reims, Amiens, Soissons and Arras, were by late 1914 back in French hands. Some of the worst damage was done to towns that were only briefly occupied by the Germans.

“64 percent of France’s pig-iron production, 24 percent of its steel manufacturing and 40 percent of the total coal mining capacity was located in the zone, dealing a major setback to French industry. A number of important towns and cities were situated within it too, notably Lille, Douai, Cambrai, Valenciennes, Maubeuge and Avesnes. Partly because of its proximity to the front, occupied north-east France was ruled by the military, rather than by a civilian occupation administration. Economic exploitation of the occupied zone increased throughout the war. Forced labor became increasingly common as the war dragged on.”

How do we calculate the value of forced French labor during the war, on top of all the other human and material costs previously discussed?

Germany also occupied nearly the entire country of Belgium during WWI, and similarly made itself welcome there:

"The German army was outraged at how Belgium had frustrated the Schlieffen Plan to capture Paris. From top to bottom there was a firm belief that the Belgians had unleashed illegal saboteurs (called “francs-tireurs”) and that civilians had tortured and maltreated German soldiers. The response was a series of multiple large-scale attacks on civilians and the destruction of historic buildings and cultural centers. The German army executed between 5,500 and 6,500[13] French and Belgian civilians between August and November 1914, usually in near-random large-scale shootings of civilians ordered by junior German officers. Individuals suspected of partisan activities were summarily shot. Historians researching German Army records have discovered 101 “major” incidents—where ten or more civilians were killed—with a total of 4,421 executed. Historians have also discovered 383 “minor” incidents that led to the deaths of another 1,100 Belgians. Almost all were claimed by Germany to be responses to guerrilla attacks.[14] In addition some high-profile Belgian figures, including politician Adolphe Max and historian Henri Pirenne, were imprisoned in Germany as hostages. "

Belgium got a share of German reparations after the war, though considerably less then they wanted and needed.