It depends if they can surround Paris (1870 style ) or have to fight into the city. I think a fight into the city would be brutal, and i see them leveling it with HA. However this would not play well into the international press.
... considering the lion's share (pun intended) of the international press was run or at least had its information supplied by the British (Who controlled the trans-Atlantic cables), nothing Germany did played well in that arena. If the men got a taste of the nightmares that might face them if they had to storm the city on foot, I think there would be ALOT of pressure to just bombard Paris into rubble. Hell, judging from the logic he laid down for the Verdun operation (and justify it post-war) Falkenhayn might see the destruction of Paris as a good thing as a way to shatter the French people's moral exactly so they DON'T get a repeat of 1870,
Is there any place in France where urban combat of WW2 intensity could have taken place?
Not really, considering the answer to urban combat is probably going to be "Use the Artillery", since it was a pretty effective tool for dealing with static fortifications (Trench networks were a slightly different story... but try digging one of those in an urban center). Unless you have an interest in keeping the city intact, there's just not a good reason to use it.
I can only think of one way: Paris is evacuated by the French following a more successful Race to the Sea by the Germans and is occupied by German troops. Supplies are stockpiled in hopes of using the city as a forward base.. During the Entente counter-offensive, however, the forces in the abandoned city are cut-off by French armies from the rest of the German lines. The French, though they want to dislodge the Germans, also don't want to shell their own capital for practical and morale/national pride reasons, and so insist on retaking it street by street with infantry, while the cut-off Germans dig in/barricade up the place in a desperate effort to survive long enough for the rest of the German army to stage a "break-in". While in all likelihood the surronded Germans would surrender and become prisoners without a REALLY good reason, its possible.