My wife and I were in a similar situation except the policy ($100k) was on her life. She was diagnosed with terminal cancer at 68. Just before that I was thinking of cancelling the policy. Glad I did not as that has contributed to a retirement in which I have absolutely no monetary worries. You never know what is going to happen. You might also want to contact an attorney to set up your estate as a trust for your heirs in order to reduce any burden at your passing.
Already done, long ago. Sorry to hear of your wife's terminal illness. My wife has cancers and has undergone many treatments over the last ten years (and surgeries going back twenty years). She has beaten most of it, and has chemo as a maintenance regimen to prevent flareups when any lymph nodes show problems.
You're right, one never knows what will happen as one ages. My wife didn't drink or smoke, exercised daily, ate healthy food and was otherwise physically fit. As for me, I abused my body with alcohol and drugs when young, don't exercise and eat unhealthy food, but I'm going strong in my late sixties. Go figure. Our life insurance is principally on me, because my Dad died when I was a teen and his life insurance helped my Mom and younger siblings get by, and I wanted to make sure my wife and kids would be okay if I passed. Everything now in our trust will pass to our kids and grandkids, although our adult kids are doing fine with their lives.