What if, having a bad feeling about the wedding of her daughter Marguerite with the King of Navarre, Catherine de Medicis chose to make it happen in a big field, with nobody, therefore avoiding one of the worst part of French history ?
As I said, Paris isn't the only place were a slaughter took place: it only was the main venue. It actually had ripple effects throughout France and slaughter of Catholics by Protestants happened in many cities. Catholics slaughtered Protestants in Orléans the day after the Saint Barthélémie slaughter happened for example. Even a city as far from Paris as Toulouse saw Catholics slaughtering Protestants, and it happend on October 4th, which was six weeks after the slaughter in Paris. And it's even hard to estimate how many people died outside of Paris because we don't have as much documentations. It's generally assumed that around 5,000 to 10,000 people died (compared to Paris' 3,000 killed) but there are a few who go as far as to say we got to 30,000.Well avoiding Paris is avoiding the slaughter anyway, because from what I know, the people killed this massive amount of protestants.
The Parisians got into the action because the assassins actually got a bit overzealous and lacked discretion... They made so much noise it attracted the attention of the people around and the situation got worse from then on. Giving the order to muder the Protestant chiefs snowballed into a slaughter yes but it was practically unavoidable given how this was done.In the assistance, people were not here to fight, the attack on Coligny was probably going to happen, but the order of execution became a slaughter only with the assistance of Parisians.
Mobs tend to be more radical and violent than their leaders.I'm not talking about the government of Paris, but about it's people, who were ultra catholics, maybe even more than their government.
The problem is that Paris, as I said, is also not just any city in France: it's the capital city. The court was mostly travelling between the various castle in the Loire River at the time sure, but Paris still remained a high center of power with a lot of institutions. There litterally was no other place to have the wedding take place if they wanted to make it a high symbol of recounciliation.Even on the paper having most of the important people of Navarre in a ultra catholic city is a bad idea. I really like Catherine de Médicis but she really missed an opportunity to be smart on this time. Paris was an unstable mess at this time, even without religious wars, that's one of the big reasons why Napoléon allowed Haussmann to litteraly bomb Paris and rebuilt street by street, he wanted the "bad society" outside of the capital.