As an angling guide on the river I would assume that you are well aquainted with specific areas including those that hold Pike.
I on the other hand have no experience of the Wye, however I believe that there are few if any waters where Pike can't be taken on lures. Take the Trent for example, it displays all of the features you describe. So yes, I believe it definitely is worth trying the larger lures in the areas you ''know'' contain Pike.
Lures, now there's a minefield, but I would definitely consider ''spinnerbaits'' they are such a versatile lure. I would plumb for the twin bladed type in the one and a half ounce range, also the newer slow sink plastics with the paddle tail, many brands available, take your pick.
Surface lures! Not my first choice for winter fishing.
Hope this helps.