Welcome!
Winter fishing is Sidney is pretty good overall, but our 62cm minimum size is an absolute pain - I don't get into keeper size fish, consistently, until February. Before then, it's good action, but small sizes.
My advice is to stick in the 100-130ft contours where it's all mud and drag the bottom with needlefish size spoons or hootchies. Glow and UV are your friends here where I prefer glow in cloudy days and UV in sunny. Troll quicker than summer chinook fishing, but slower than coho and you'll be golden - make sure to keep your balls on the bottom. If you stay at the above depths, there isn't much rock/weed/trap around to take your lead away.
Spots:
- Coal Island, between the North-East Point and the Islets to the south. beware the reefs! Usually holds lots of bait and is a very consistent producer.
- Sidney Channel, from north of Sidney Spit (beware the lumps, for they hold derelict traps!) all the way down the length of the island to James Island and Powder Wharf.
- Miner's Channel (East side of Sidney Island). Start north of Sidney Spit and troll the whole length of the island. Really useful when the tide is burning as you can fish one way on one tide, then the other way.
- Fairfax Point, Personally, my least consistent producer in the winter and with the longer run time (12 minutes from the ramp), I don't go there that often. But very nice on a strong ebb as the island provides cover. Work up to the point, then turn around and repeat.