I assume lake Pike tend to be in deep water in the winter because that is
where the food is? What's the best way of locating them, except for
spinning?

Does plumbing/feature finding scare them off. The reason I say this, is
because whilst watching Pike from a bridge over a local river, I found they
are actually quite shy, and will move off at the slightest sign of
disturbance. Maybe they only move off temporarily though? Or maybe they
find another ambush spot?

Alternatively, instead of going to them, can you get them to come to you?
Especially in featureless lakes. Are there any flavourings which you can
inject into a dead bait to draw Pike in, except fish smelling flavourings?
I was just thinking. Having a deadbait in the water, you would think the
Pike would smell it and come rushing. But can a Pike really tell the
difference between a dead fish and a fresh deadbait by smell, or do they
just come across them? To me, they smell the same.

Maybe PVA friendly 'Blood' or 'Decaying Fish' flavouring or something. If
you look at people Shark fishing, they empty bucket loads of blood and guts
around their bait, and it works.

Someone said that Rod Hutchinson 'Shell Fish Sense Appeal' boilie flavouring
works for Pike, but I am not sure.