Like you,Andy, I would try starting in 5th Position on the A string and keep shifts initially small. The warmer sound fits in better and you have the certainty of the thumb anchoring the position of the opening notes in this exposed passage.
So, F C A topF D C(on G string) A C D C A F(on D string) G C. becomes. 1 4 1 4 1 ....1 (III posn), 4 1 4 1 4...1 4 1
I would try this for desirable warmth of tone, initial stability of bow contact point, security of IV and V Positions and smaller initial shifts for smoother legato