I’m trying to book an International Flight ticket on December 26, but I have an 1h:30m layover in Chicago. Do you think that would be an enough time to get to the other flight in that time of the year??
If you are leaving the US from Chicago, then that should be plenty of time. If you are entering the country in Chicago, then that will not likely be enough time because you will have to go through Immigration and Customs.
Assuming the flight is not delayed arriving to Chicago, you should have enough time. Chicago unfortunately can be quite congested with so many flights departing and arriving. Also you don't know how the weather will be that day. If there is a lot of snow on the ground, there can be delays, even though the airport has a good snow removal system.
If the airline is showing you that as linked flights, then they think it's enough time. 1 1/2 hours is normally plenty of time, although at that time of year, there's always the possibility of flight delays because of weather. The last time I came through Chicago, last spring, they were re-doing the train between terminals, and everyone had to go outside to get a bus from the international terminal to the domestic terminal and vise versa, and go through security again, and it still didn't take an hour and a half. If they've finished the train, it will not take much time at all to go from one terminal to the other.
It should be enough time, but if you have a choice, allow yourself another hour. At that time of year it could be very crowded and all the usual processes might take a lot longer than usual.
I always prefer to have too much time. It's much nicer to sit down with a coffee for half an hour or even an hour, than to panic all the way through the airport in case you're late.