Det verkar som om deras ansträngningar i slutet av kriget var tillräckliga för att få dem ur kroken med Harry Potter wiki säger:
Because he and his family defected from the Death Eaters they were pardoned for their crimes after Voldemort's final defeat and did not serve a stint in Azkaban. He and Narcissa later had a grandson, Scorpius Malfoy, after Draco married Astoria Greengrass.
Betona min.
Som Jenaya påpekar i kommentarerna kan Harry Potter wikien inte vara den mest tillförlitliga och så använder de sina länk till Pottermores sida på Draco Malfoy , kan vi hitta ytterligare stöd:
Following the battle, his father[Lucius Malfoy] evaded prison by providing evidence against fellow Death Eaters, helping to ensure the capture of many of Lord Voldemort’s followers who had fled into hiding.
En liten extra information om sina liv efteråt kommer från sista stycket om Dracos liv:
Draco married the younger sister of a fellow Slytherin. Astoria Greengrass, who had gone through a similar (though less violent and frightening) conversion from pure-blood ideals to a more tolerant life view, was felt by Narcissa and Lucius to be something of a disappointment as a daughter-in-law. They had had high hopes of a girl whose family featured on the ‘Sacred Twenty-Eight’, but as Astoria refused to raise their grandson Scorpius in the belief that Muggles were scum, family gatherings were often fraught with tension.
Så det verkar som om Lucius och Narcissa vände sig mot Death Eaters i slutet blev de inte mer toleranta mot muggles eller halvblod i processen.