It's not just a bad idea it's a terrible idea OP.
You have a husband that loves you, bet he's up for a bit of excitement as well.
We are a bit older than you both, with teens not adults and yes I guess you could say day to day life is boring and stressful right now.
Still guiding kids towards adulthood. Bereavements and older relatives, plus our own longevity to consider.
But by god dating the 50s-ish online lot is not the answer. I occasionally read some of the hilarious and beautifully written dating horror stories on here and one where a first date man got so cross, threw a shoe at a swan and it landed in a lake still has me howling. So if that is the sort of dreadful excitement you are going for then fill ya boots. Being whisked off to Lake Garda to share wine with a successful silver fox who just hasn't met the one and had been waiting for a woman like you to enter his sphere, it is not!
Write a fantasy novel like Jilly Cooper (guess who's been watching Rivals) you never know it might be a hit, get all your fantasy out another way.
Walking back to a car, after a mediocre drink you had to pay for yourself with an angry reject of a man now with one wet sock is not worth blowing up a 20/30 year relationship with someone who puffs a little because you point out you watch(ignore) plenty of live sport so it's Rivals evening, but still makes you a tea/pours a wine, rubs your feet, with great sex on tap, pays when you go out because he does notice everything you do, puts thousands in a pension so you will both have choices when he retires early, loves your kids as much as you do, attempts to be a grumpy old man but gets nowhere because you point out you are ignoring him now and I can absolutely say would never throw a shoe at a swan in anger.
Sounds like you have already navigated so much together already, working out how to navigate how to inject a bit of excitement or even a bigger change for the coming years together should be a piece of piss.