When will NON-"kiddie table" Republicans start dropping out?

[°Leprechaun]

For the "second tier'
As early as the last week in January
As late as right after New Hamphire

This is the order I predict from most to least likely to drop out:
Fiorina, Bush, Kasich, Paul, Carson, Christie
Just a random guess, based on the unpredictability of this election

The others are becoming less and less important
third tier undercards:
Gilmore, Huckabee, Santorum