Rabbi Moshe Kotlarsky related this story:

My older brother Yaakov Dovid, of blessed memory, was born during the holiday of Sukkot; hence his thirteenth birthday, his Bar Mitzvah, was also during Sukkot. My parents, Rabbi Tzvi Yosef and Golda of blessed memory, wanted to make a grand celebration to mark the event, especially since it would be the first big simchah our family would celebrate since the Holocaust. Considering that during Sukkot all meals are held in an outdoor hut known as a sukkah, my parents planned the event for the Saturday night following the Sukkot holiday (after Shabbat ended). This way they could invite many guests to celebrate the Bar Mitzvah in a spacious hall, as opposed to a small outdoor hut, which would have severely restricted the guest list.

Prior to his birthday, my parents and brother had a private audience with the Rebbe, of righteous memory. During the course of the audience, the Rebbe asked my parents when they are making the celebration. They responded that they were scheduling it for after Sukkot.

The Rebbe wasn't happy with the idea, and suggested that they hold the celebration closer to the actual birthday.

When my parents explained the predicament they faced, fitting everyone they wanted to invite into a small sukkah hut, the Rebbe responded that they could build a bigger sukkah and if need be invite a lesser amount of people...

And that is precisely what they did. They made the celebration in the biggest sukkah in town, the one near the synagogue—with a somewhat smaller invitation list.

Prior to my thirteenth birthday, I also went with my parents for an audience with the Rebbe. On that occasion the Rebbe told my parents that based on the Talmud's statement (Shabbat 10b), "One should never differentiate between one child and the other," the celebration of my Bar Mitzvah should be done in a similar fashion as my brother's, not bigger or smaller.

My parents followed this directive, both with regards to my Bar Mitzvah as well as my younger brother Mendel's.