The closed airport, cancelled buses (Not in Bristol, but yes in nearby Bath) and postponed football matches was due to the icy, and slippy conditions on the roads, and footpaths on the 18th. Not the depth of snow itself, there was an inch dusting in Bristol and surrounding areas. It plays a big factor regarding covering a body, or not covering a body IMO.
The BBC reported rather more snow than that on the 18th:
http://www.bbc.co.uk/news/uk-england-bristol-12025793
"About 2in (5cm) of snow fell widely across the city on Saturday morning with more reported in rural locations to the south of Bristol".
Failand is on relatively high ground to the SW of the city and may well have been one of the rural areas more badly affected, as the snow came up from Devon. There was also a report of 10cm of snow in Portishead, to the west of Bristol, that morning.
As I recall, the snow before Christmas was very uneven - some areas got off fairly lightly, but often there was very heavy snow just a couple of miles away.