I often get to a situation usually one from the bubble at level 5, where I have a possible push opportunity. But the BB has not yet called an all-in or not had the chance to call an all-in. So how to estimate a calling range?

Would their general tightness pre-flop relate closely to how they would play against an all in?
If I estimated from the VP$IP figures on them, would the average 33er call a push only with a better hand than their VP$IP suggested they would see a flop with?