Texts may be produced, it can be argued, in compliance with or against the strictures of an established and identifiable genre, though it is equally feasible to impose a genre identity upon a work in retrospect, thus attributing to it further possibilities of meaning or, conversely, limiting its potential signification.
We get no snow. The full sized horses are blanketed at under 45 degrees with a sheet or medium blanket. We rarely ever use heavy blankets, except for with our 49 and 28 year old mares. Both of them wear a sheet at under 55 degrees, due to low body fat. So really, you just need to look at all of the variables.
Sometimes a quarter sheet size is the horse's equivalent stable blanket size. The quarter sheet described above would fit a horse that would wear a size 78 blanket (197 cm) so sometimes the sheet is referred to as a 78, but it is not 78 or 197 cm long. All of this varies greatly with sheet design, country of origin, and the manufacturer.