How to Keep Warm
geedavell,.... Maybe your description of your wife'll give you an idea about the answer to your question, "....a fair weather angler??" at 50 degrees she might be OK with it but at 20 degrees (more likely) she'll be uncomfortable unless she's familiar with doing things in ice/snow.
I'd recommend you leave her at the home or hotel you'll be staying at (especially if there's a hot tub or book/good food involved).
If you still want to bring her along, make sure she dresses in layered clothing and good luck.
"America is a country which produces citizens who will cross the ocean to fight for democracy but won't cross the street to vote."