And, don't forget that the danger zone gives you up to four hours in it. While I wouldn't stretch it to 4 hours, you've got a good three hours after it hits 140.
Also, as someone else said, you could put it in a slow oven and just keep it warm. Just put it on the lowest setting. On my oven, it's 170.
I'm also guessing that even if you let it get below 130, you could just pop it in the oven at 250 or so and bring the temp back well up above 140 in an hour or two. Since you've never pulled it and it's never gotten "cold", it will probably be just as tender. All you've done is make it longer and slower. I'd take it to 160 - 170 just to be on the safe side.
I've never done this, and others who have might have a different experience, so take this with a grain of salt. But I can't see any reason why it wouldn't work, especially since you can refrigerate pulled pork and reheat it to perfect condition.