My friend's father died when we were in high school. His widow (my friend's mother) switched her wedding band over to her right hand.
I thought this was wise - it was a reminder of her late husband, and yet didn't immediately show that she was married. She was young at the time 40ish) and did remarry a few years later.
At this point, with me being 64 years old and married 33 years, if my wife were to die before me, I doubt I would remarry. There's so much love and so much great shared experience that I think I would prefer to keep busy with family and friends rather than try marrying again.
Besides, I'm quite nerdy and introverted and have offbeat interests and a weird sense of humour - not exactly prime dating material.
But in any case, both of us seem to be in good health, so hopefully we'll have many more years together.