I have fished the reservoir in the past . The eastern end for the most part small perch but with larger bait would pic up rainbows. Shallows for the trout be carefull of the channel this early . I usually hit it later in the season its a big area and almost always was the only fisherman on there but lots of sleds.
I have used a two wheel drive wheeler in the past there also after the snowpack has melted to refreeze into the ice pack Power augers help with this scenario ,two feet of ice can wear you out drilling all day. Also be carefull in the shallow with your auger walked two miles to a point i fished in the summer drilled away from the point when it went through the ice went right into sand and rocks
Look at the sled trails and gauge if you want to venture always check as you go also the water is always flowing into a lowered reservoir and can create, slush,pressure ridges, weak spots etc. not to mention the river aspect. I have been told , but not witnessed , that someone drilled through there and the water was a foot below the ice .
This was from 95 -2004 before they put in the launch near the dry hydrant in redfield ,Had to get there early for a parking spot with the snowmobilers. Call Great White North in Williamstown They used to have reports for there . I Don't know any current conditions or how far down they draw it down now. Good Luck.