I'm considering wearing this dress for an upcoming wedding where the dress code is semiformal and could really use some advice. It's a winter wedding and they've requested no one wear black, so I'm trying to figure out if something I already own could work, and this is my only non-casual dress that has sleeves and isn't obviously meant for warm weather :/ It hits about mid-thigh (I don't think it looks mini in a clubbish way, but I'm pretty tall and at this point am used to everything just being shorter on me so could use an outside perspective) and while it's a plunge neck it doesn't show a lot of cleavage on me if that makes any difference. Should I be looking for something longer or more formal in some other way?

Also--what kind/color of shoes would I wear for this if it is wedding appropriate? In general I have no idea how to handle that this wedding is happening during the winter. It's indoors, so I guess if nothing else I could just push through the cold during any transitions, but would it look weird to have strappy/open toed shoes?