The ScubaPro EveryDry is a neoprene suit. Such suits have drawbacks (like not insulating well in deep water, and being a little harder to manage from a buoyancy standpoint) but for the purpose of your shallow dives, it might do you quite well, and would certainly reduce the amount you need to wear under the suit.
On the other hand, I have a whole crew of friends who routinely ice dive in the Ontario area, wearing laminate dry suits and good quality undergarments. If you are wearing five layers, I suspect you are wearing stuff that wasn't designed for diving. When you do that, you end up with more bulk, more buoyancy, and less efficient insulation than you do if you go for purpose-made garments. If you're looking to upgrade your insulation, rather than buy a new suit, I'd invest in a really good diving undergarment.
On the other hand, I have a whole crew of friends who routinely ice dive in the Ontario area, wearing laminate dry suits and good quality undergarments. If you are wearing five layers, I suspect you are wearing stuff that wasn't designed for diving. When you do that, you end up with more bulk, more buoyancy, and less efficient insulation than you do if you go for purpose-made garments. If you're looking to upgrade your insulation, rather than buy a new suit, I'd invest in a really good diving undergarment.