Hi Guys
I use the same as you do in summer but winter fishing can become a cold experience,so much so that you return because of coldness. We have used for many years thermo vest for canoeing in winter time. Now remember the Highveld is much colder in winter than at the coast. The material of the thermo vest takes the water away from you body to the outer layer of the material. This ensures then that you are not wet all the time and have a reduction of body temperature. These vest are normally available at outdoor shops or sport shops. They are unfortunately a bit costly +- R300-R400.
Luckily is it now summer so fishing is also heating up.
Cheers