Mobile game and lighting?

Question

C++ / C#

Comrades, we need your help, because. already confused.
Given: mobile game, BIG city, change of day to night.
Now, when developing, when 1 light source (direct) fps is normal, but as soon as other sources appear (such as lanterns, poles, etc.) (and there will be many of them), the fps sags a lot, because. real time lighting.
The main option that comes to mind is to bake all the lighting. BUT THERE ARE A LOT OF PROBLEMS HERE: the size of the lightmap will be HUGE and will take a lot of resources, not making the day/night cycle adequately, and houses have a lot of materials.
Question:
- share your experience please
- is it possible to bake ONLY lamps, but WITHOUT global light?