Yes, you don't have to join in a group. These sculptures of the festival will be shown in the parks of Harbin and the Ice and Snow World. You could get the details at: https://www.travelchinaguide.com/attraction/heilongjiang/harbin/ice_snow.htm

Even at late night, you could take a taxi to back to hotel easily. Well, it is suggested you book a hotel around the city center, from where you could reach other parts of Harbin easily.