Pacific gopher snake vomits?

[Sethu]

On thursday, I fed my ~2 ft long pacific gopher snake a mouse that was slightly too big, I didn't realize it was that large until the snake had already swallowed it. He swallowed it easily and for the next few days the lump was shrinking and all was fine. But when I woke up this morning (sunday) I found what looked like the hide of the mouse with nothing in it, it was gray. I'm wondering if this could've been caused by the mouse being too big. Or perhaps it is because I've had a very tough time keeping the temperatures up and they usually sat around 80 ok the warm side rather than 85. What should I do about this? Wait another week and feed something smaller, and if it happens again take him to the vet? Thanks.