No matter which you choose, constant emersion in vey cold water
is going to put you in some tricky situations healthwise. Wade fishing in winter is bad but you are spending some time moving oustide the water and rebuilding heat/blood flow to your extremities.
I used heavy 4 mil neopremes in my float tube and, still, long exposure in early spring got my legs cold deep to the bone and they stayed that way for hours after. Combine a brisk wind that wicks away heat above water and you can the get close to margins where your body sucks heat to the trunk area, your brain gets fuzzy, and thermal shock can snuff you.
Be aware of the signs of a thermal shutdown and take precautions. Periodic walks on land or heating up in your vehicle with a coffee etc.. can help avoid such problems.