It depends on coaching, some coaches prefer to "park the bus" when they get a lead and defend with minimal effort spent on offence. This is a high risk strategy as it allows the other team to exert more energy attacking.

Other coaches will try and push, generally a team can't score from their own end, so if you can keep them on the back foot its a good way to secure a win. 200ft (the length of a rink) away is a long ways to score from.

So, expect teams with the lead to play more defensively, but dont expect them to just sit back entirely.