In the Fall/Winter, you would fish the brush piles at whatever time of day the air temps allow you to ... IMHO.
Trolling is simply fishing with the boat constantly moving. What baits you're using and what rigging style will determine what type of "trolling" method you use and at what speed your boat is moving. You have longline trolling, Spider Rigging, & pushing/pulling as the most often used terms to define what method of "trolling" is being done.
You definitely want to have quite a few brushpiles marked, and know at what depth they top out at vs the water level. Then when you find a few fish on a brushpile, you'll know which other piles are at the same depth and can move to a fresh one if you stop catching fish from the one you're on. You can set up a "milk run" between several piles in a localized area, and jump from one to the other after catching several fish from the first one. This gives them time to settle down at each pile, after you've removed some from that pile, and then you can make the "milk run" several times (if time permits) during your trip.
... cp