I am currently in the same situation. I fished the GNWC last year out of a 16’ Lund and fished on Green Bay and Bago, can get plenty nasty on either. We took some 3 footers through the year, but saw what “real” rough water can be like on Erie (in a 18’ glass boat). I am upgrading to a 19’ glass boat.
I have three reasons for my upgrade.
1. Safety (and feeling safe)
2. The ability to make a run if needed. I couldn’t do this in my little Lund
3. The FLW Walleye League requires a minimum of a 17’ boat
Your Crestliner is a nice wide boat but is not all that deep or heavy, perhaps something in the 18’ foot range would suit the bigger water a little better. The nice thing about 18’ and over is the length helps when trolling with waves (the front end doesn’t spear as much with the longer boats). I don’t want to get into any suggestions on brands here because there are many good brands now, just that you want something designed for taking bigger waves and being comfortable in.
Send me a PM if you want a few boat suggestions, as I have looked at all of them in the last few months.