I don't have a set behaviour, it depends on several things such as the meta, what cards are available and what decks I like etc. I've played one deck and only one deck for a couple of weeks before, because I've found it a very fun deck. Other times I switch between decks every few games, because there are multiple decks I like.
It's not very often I use a deck 'to climb'. I generally find that a good number of decks can get you up the ladder so I typically just roll whatever I like actually playing.