Early Lighting
Here’s some lighting tests. The first one shows the bare minimum setup: directional lights for the sun and the bounced light.

Here’s the same thing but adapted into a more standard three-point setup. Using warmer tones to try to indicate the sun’s position. The softer shadows make it less cartoony, but it still has a very stylised nature.

One more; an attempt at making it more realistic.

The setup needs some work; at the moment the near hills blend into the far hills too smoothly.
Also, shadows need to be addressed. Everything has very soft shadows at the moment, which is suitable for an occluded daytime scene, but the bike needs something to ground it. One idea I had was to render the bike from above and create a projecting ‘gobo’ parented to it. This could project a shadow directly beneath it, which could be soft in the right places.