Then treat a self signed HTTPS cert as equivalent to an unsecured HTTP connection and be done with it.
There's absolutely no reason that the most common failure modes (expiration, bare domain vs www., self signed) presents warnings that Something Fishy Is Going On®, when 9999/10000 times, there is not.
Smoke coming from my neighbor's yard in the summer might be a fire, but in all likelihood, they're running a barbecue grill. The SSL equivalent would be calling the fire department every time someone puts some steaks on.