Alright, more anecdotal climate data, coming right up!
When I was growing up (and I'm 30, so not all that long ago!) we could skate on the
pond here at my parents place, some winters. It's been quite a few years since a freeze like that. The main downside is, it doesn't seem to be just the winters getting warmer; it's the summers, too. Warmer, and drier. A good water supply and land that will readily accommodate
earthworks for water storage are critical.
I would say that in Victoria there was one real winter in the last 5 years; while I don't remember which year it was, I remember walking to work on the very sketchy compacted snow/ice for several days in a row.
Microclimates will have a huge impact on a site. See if there is an older resident who's been there for a few decades. When I lived in town, it was common for my parents ~15KM up the Saanich peninsula to have 2-3 pretty mild snowfalls, a few inches to a foot, while in the city nothing would stick, if it even came down as flakes. A friend living in the Willis Point area another 15 minutes away would have twice as much pretty reliably.
The only 'serious' winter in my lifetime was the blizzard of '96, when my parents house had 6' snowdrifts. I have no idea what it was like in town, since we were snowed in for days despite having a 4x4 truck. Our neighbours house collapsed under snow-load. Being a kid, I thought the whole thing was pretty wonderful, except my pet fish froze to death while we were in a hotel for xmas, after we dug out the 100M driveway, and a tree took out the powerlines and a chunk of the roof...
The farm I interned on last summer was 5 minutes drive from Duncan. Several times through the summer someone would be in town running errands, and it would rain. Most of the time the farm saw none of this rain; the neighbouring hills would shunt the clouds the wrong way. On the hottest days, it would be 10-20C hotter in the low fields on the farm than the coast ~5KM away. The heat-pocket would become a cold-pocket in the winter. I visited in late winter last year, and there was a foot of snow on the farm, compared to nothing at the highway 1.5KM away.