On Jan. 9, Tonja Stelly had to be in two places at once. That’s nothing new to her. It’s become a tradition over the past three years, whenever the NBA and NHL schedules collide in just the right way. The Knicks were playing the Portland Trail Blazers inside the world’s most famous arena, Madison Square Garden, that Tuesday. Her son Quentin Grimes, a guard with the Knicks at the time and currently with the Detroit Pistons, had a 7:30 p.m. tipoff. Twenty miles to the east, her son Tyler Myers, a defenseman for the Vancouver Canucks, had a game at the same time, against the New York Islanders in Elmont, N.Y .