With regard to the wind, that is a more or less permanent feature in
Winter on the Baltic, so what a few of us do is use it to our
advantage. As you quite rightly say, it is more or less pointless
trying to fish properly from a constantly moving boat, and the wind
will also blow you away pretty fast which could be very dangerous.
There are only a few pontooners on the Baltic in winter, and virtually
no float tubers. it is just too cold and dangerous for that.

Anyway, those of us who do pontoon ( did, in my case, I am getting too
old for that now) use a longish anchor rope ( say 30-40 meters at 6m
water depth). lower the anchor, pull it in with a reverse breakaway
knot, and then pay out the rope anchoring the boat by the stern
stanchion. ( you can see the anchor winder on my boat in the picture).
The wind blows you until the rope is more or less taut, and you
commence fishing. You do move about quite a lot, but it serves well
enough as a fishing platform. This also ensures you have the wind at
your back, making it easier to cast and fish, and you don´t ( seem to)
get so cold so quickly.

TL
MC