Basically, the game tells you that there is a time limit, and encourages you to move as quickly as possible, and it's only when you do rest several times that you get told that it's not progressing as quickly as it should.
In fact, there's no time limit at all, and you will be punished for not resting after every event - that is, you will MISS content unless you rest nearly constantly after every major fight and every event that occurs. The game undermines itself quite badly in this respect right now.
Chances are if you've been 'holding off' then you've already locked yourself out of some content paths with at least one of the companions, due to not resting frequently enough to see all of his content.
