I think it depends a lot on a person. Usually for inmer planets around 4 degrees before conj, after it the effects are weakened in my experience. For outer planets, prolly 2 orb before conjunction. Again it depends a lot on you if you gonna still feel it after the conjunction. I personally don't. It's most intense before and at the moment of the conjunction, however it also depends a lot on your own chart. For example, Saturn is the strongest planet in my chart, and when Saturn was conjunct my Sun I didn't feel much different, cos my sun is Cap anyways.