The Annual Broom Race of Sweden is a dangerous 300-mile race between Kopparberg and Arjeplog, first run in the 900s, and which has since become a popular international event. The racers must travel through the dangerous dragon reservation that lies directly between the starting and ending points. The spectators avoid the dragons by Apparating between the start and end points, but the racers must elude the fierce beasts and some do not survive (QA2).
The actual distance between Kopparberg and Arjeplog is 435 miles. Neither Kopparberg nor Arjeplog existed in the 10th century when the race began - nor for that matter did the country of Sweden.
Kopparberg is often associated historically with the copper mining enterprises around Falun, which is somewhat closer to Arjeplog (385 miles) but still quite a bit outside of the range mentioned in QA.
Sweden does hold an annual ski race - the Vasaloppet, commemorating the 1520 escape of a future king (Wikipedia).
From the Web
Harry Potter Wiki: Annual Broom Race
WizardingWorld (Pottermore) features:
Tags: brooms / broomsticks dangerous distance fans international Quidditch history racing brooms speed