Around 8.09 a.m. on Saturnday 22nd December 2018 the sun will rise at its most southernly as seen from the Stones.
But the Drove will probably be blocked by the alleged ‘authorities. , English Heritcage are opening their carpark at around 6 a.m. but refusing entry when its closed. See https://www.english-heritage.org.uk/visit/places/stonehenge/plan-your-visit/winter-solstice-at-stonehenge/
STOP PRESS – the order closing the drove may have been quashed in court today