Kid Flash's cross country run to deliver a donor heart is based on Flash (Volume 2) #1 (1987). In that story, Wally had to deliver a heart from New York to Seattle on his twentieth birthday, and encountered Vandal Savage along the way. However, in that story, Savage's presence was a coincidence, not a planned delaying tactic.
On the news report, Iris announces school closures: Spisak Junior High, Keystone High, and Central City High. All three schools are references to Flash: Spisak Junior High is a reference to Jason Spisak (voice actor for Wally West/Kid Flash in this series), Keystone City- Jay Garrick (Golden Age Flash), and Central City - Barry Allen (Silver Age Flash).
One of the schools mentioned, Spisak Junior High, is named after Kid Flash's voice actor, Jason Spisak. Dubuc Elementary is named after Nicole Dubuc, Iris West-Allen's voice actress.
Ariel Winter also voiced Robin (Carrie Kelly) in the Dark Knight Returns Part 1 & 2
Wally tells the transplant team he is running just shy of the speed of sound (Mach 1 is 767 at sea level). This is supported by the time stamps of his trip; he runs from Boston to Chicago (850 miles) in 83 minutes, a speed of 10.2 m/minute, or 614 mph. Because of the icy conditions, this may not be his top speed, though. Using this formula, it can be reasoned that Happy Harbour is no more than 200 miles from Boston.