Freezing a brain in liquid nitrogen destroys the pattern utterly. It is theoretically possible for successful molecular fixatives to be invented in the future, but at this time, there is insufficient reason to expect existing techniques to result in eventual recovery.
Does PascalsWager apply to freezing your head? The common argument put forward by cryonics advocates is that freezing yourself may be a long shot, but it has to be better than cremation or burial. That would be true if those were the only choices, but it is possible that your money would be better spent on research in longevity, uploading or some other technology.