This next is a phrase I use a lot. I don't even think about it. When you're north of the Ohio River, you know when you say things like "I reckon" and "you all", people notice. South of the Ohio, everybody says it so no one thinks anything of it. I'm very familiar with that. But once, up in Maryland, I got caught with a "might could" while talking about a programming problem. The person I was talking with took note, then asked me to repeat myself. I had never even given the phrase a second thought. To me it was common as rain.
Might could can mean anthing from "I'm not really sure" to "I'm absolutely positive". You have to know the personality of the person saying it, and the situation it which it is used.
"I might could do that" - again, the speaker may not be sure, or could be absolutely positive. It just depends.
"I might could git that for you, if you ask me real nice".
Might could. A nice phrase, especially if ambiguity is needed.
A note on my previous post. Sorry about gloating about how warm it was. It's now turning cold again, so that put me back in my place. I actually have no control over the weather. I might as well gloat about the sun coming up in the east.