Well Ron Dennis when asked about it evaded the question and replied with the standard PR "the team thsi the team that".
LH pre-race hinted at the tyre warmup issue and reckoned that would give them the advantage. I strongly suspect that is why he is feeling so confident. If you know your tyres are going to be working better than your rivals then half your work is done.
Of course Ferrari deny it when it puts them at a disadvantage but they also are quick to praise it when it puts their rival at a disadvantage at a hot track
Swings and roundabouts..