i wouldnt want to be without the windshield on the lake, it will block most of the breeze in your face (so will the right helmet).
when I did my first service at the dealer I had him add the hand/thumb warmers... they're nice and I like them, but if you're wearing too thick a glove you may not feel them for a while. I'm sure they help though. Its kind of like air or sex... you dont notice it until you're not getting any
 

  I have both hand and thumb warmers on  my bike. The problem I have is my throttle thumb always gets cold for  the first ½ hour of a ride, even with thumb warmer on hi, I'd hate  to see how cold my thumb would be with out the heater. This is  something I've experienced even when I was sledding. After that I'm  good for the day. The handle bar warmers are great, often you can  drive the bike wearing lighter gloves.   
I have a windshield for my bike. I  found when I'm wearing my floater/survival suit I don't need it. If   it's calling for really cold weather the windshield is on. It is  great for trail riding in the cold weather when I'm wearing my old  snowmobile gear. The windshield is designed for quick attachment and  removal.   

I have the hand and thumb warmers and the thumb warmer is a definate must  because your thumb slightly bent gets fatigued and cold quick . My windshield too helps keep a driving wind off my chest and if your following somebody you wont get hit with a stone or chunk of ice . It also gives you some protection if you dont have a remote winch and the cable snaps . Even sticks and brush . I need to replace mine for a reason soon... and its not because I run hard or fast because I don't, but because its saved me getting hit numerous times .
Mind you although I own a full face helmet ; I never use it because it constricts my peripherial vision and makes me feel claustraphobic . I like to look around and I'm always hunting;fishing and trapping year round just to see what mother nature is doing .. Just because a season is closed does not mean we can't look . We just dont harvest and as it should be .
I ride with a few friends that even miss seeing monster moose because of speed and full face helmets .I putt,putt mostly watching and looking for sign..I'm never in a hurry .
Another add on I like is my mirrors especially icefishing . I can see if I've lost my sleigh or gear this way . I keep an eye on it . My auger for the most part rides on rack up front because its longer than my bike is wide and I know exactly where it is and if it;s vibrating or taking a pounding while getting loose . Also I can see to steer around the tree rather than cut it tight without looking back and smash it off .
My windshield is the basic one not the fancy surround fibreglass one .
I ride easy and dont like stones or dust in my face  .I have a small bike that drives on fumes but I always get my clients home safe . LOL I get a 150 klicks to a tank anyway and it starts at 40 below . plows etc . all i need and perfect for this trapper ..but not for everybody .lol   Dont ride with me if your in a hurry . lol
TD