At least one reason for the lower number of questions is that Travel is a seasonal activity and thus we end up getting more or less questions depending on the month. Here's a graph plotting the number of questions we get per month over the past 5 years:
Northern-hemisphere summer months are consistently the most popular and the months of October, November and December are consistently the least popular. So I'd say the situation is close to normal, although the Monica situation might indeed have affected it to an extent.
Besides the normal going up and down we usually have, the situation with Monica means that a lot of regulars do less or nothing on the site.
It is not as visible on Travel as it is on some other SE sites but it is certainly visible when you see several of the long time regulars not posting much or at all.
Some of the other SE sites only get questions of new users, non of the regulars, and if they do not have many questions from people finding them on search sites, they look dead in the water now.