[Capt. Lou]

This basic premise is correct,what causes & acclerates turnover is a mentioned a cold ,preferably windy front. In essence what occurrs is the lake water beconmes cooler than thermocline water & this now heavier water drops thru to sink to bottom.
This occurs to the point where the temps willb eunifrom top to bottom for a short time than the upper layer will become colder while the bottom thru winter will usually retain a temp of 40 degrees or so while the top will obiviously get to freeze point.
This is the hardest time to fish big water unless you cover all depths or any outlet / inlet that may provide temp variations. Pay attention to wind direction, the winward will generally agitate bait & water movement sans temps,sometimes a good place to be especially in spring! Contours that sustain higher temps for any reason can also be hotspots, use a good DT gauge combined with lakje chart to explore each time you fish in fall.
A modified SG is waht I used this time of year to key in on a variety of depths on the troll.
This can also be accomplised with a DR by stacking, but in heavily fished lakes I went SG rig or LC trolling line .
This methods refers onlt to troll for trout species & the like that temp plays a big part in their lives & food sources.
I loved trolling or jigging big water & did so for over thirty seasons learn how & your catches will increas & become more consistent.