Vietnam has been under the rule of many different governments which is why you would observe that it seems to be an amalgamation of different cultures which is what attracts people towards it. Vietnamese Tet refers to Vietnamese New Year which is celebrated in spring and the country turns into a magical place during this time due to the many activities taking place. You might be getting an ancient town map for Hoi An but we would suggest that you visit that city later and go to Ho Chi Minh to celebrate the Tet.
We cannot stop using the word magical for Tet in Ho Chi Minh because it is just that. The city knows how to celebrate the new year and it goes all out in doing so. If you get out on the streets during the days up to the main day, you would find entire streets with people mingling, amazing artwork that is made up of different things and decoration of lights that you might never get to experience anywhere else.
Yes, you heard that right! The city offers special food just for Tet and the food that you would find during the days leading to the new year are considered to be propitious which is why it is only reserved for these days.
The people living in the city usually go out of town to visit their families in villages or other cities so foreigners can enjoy a quite time there, without any traffic.
You would be able to easily find hotels of your liking in the city so do not worry about your accommodation.
Since Tet is in spring, you would not be subjected to bad heat and would love the weather.