Green’s Dictionary of Slang

totally, recklessly committed.

1630		J. Taylor Works ii 145: For where true courage roots, the proverb says, Once over shoes, o’er boots [F&H].
1687		J. Phillips [trans.] Cervantes Don Quixote 179: But when he found himself over Shoes, over Boots, and that his Heart was all of a Blaze, beyond the Quenching of the City Engines [...] what a Clatter was there?
1840		Marryat Poor Jack 360: Bessy’s in love right over the ankles.