I would try the sand bar southwest of the 135 deep area on the line marked 3/10 look for a spot between 15 and 25 feet on the sand near a drop if you are fishing in the day. If you are fishing at night I would fish in the same area but head farther to shore to find an area about 5 to 12 feet deep idealy in sand next to a weed edge. If you cant find an area like that for night fishing find a spot whare the weeds are about a foot and a half tall an five to eight feet of water between the top of the weeds and the ice. Although I want to point out that all the information I am giving you is based on two lakes near me that I have spent thousands of hours watching whitefish through the ice on. They may not act the same on your lake, the biggest problem will be finding the three to four week time span when the will be spawning, around hear it starts the week before christmass regardless of weather or ice conditions, some times it is still open water and other times we have 10 inches of ice at that time of year but like I said that dose'nt bother them, they start running right around the week befoer Christmass.
I have heard that up north farther there are some lakes whare they spawn near creek and stream outlits all winter long, but Ihave no first hand Knowalage of that.
Good luck, hope you can find them.