Currently if I put my sign outside someone like Mohg or Melania, I get summoned instantly. But I hardly see and gold signs down unless it’s a popular area.

If you go too far you'll be locked out entirely bc nobody is near you. I imagine you'll already be limited as is. Are you matching places outside haligtree, Maliketh and final bosses?

So I just finished the main game at level 150. I haven’t levelled since and haven’t started journey 2. Should I remain at level 150 so I can still play with others and get invaded? ( I like being invaded at times ). Or will being too high a level stop my sign and others appearing? Would like to get my faith to 80 and be able to cast sorceries and incantations with others in new game+. 

Thanks.

Level recommendations for maintaining co op capabilities ( invasions, summons ) in Journey 2?