Tuesday I rode 25 miles each way to spend 5 hours shoveling then stopped home long enough to refill a bottle and went for a 50 mile ride to a bike shop. My wheels are untrueable and warped from the salt and below zero exposure on my 30 lb commuter.

I think that you should either go farther afield or discover a further obstacle to overcome if you are getting complacent. Given your answer regarding centuries, riding till you puke is not going to be that challenge. Perhaps you could try being a randonneuse and haul a proper picnic basket to the idyllic hilltop vista of your choosing.