Finn was about to fight Kylo Ren in that snowy environment. Rey seems to be crying over someone in a similar environment. The right side of the figure seems to be hairy like Chewie, but the left side does not. I think it may be Chewie holding a dead or injured Finn.

He may have been holding a lightsaber, but I still don't think he's a jedi. It is Luke's old saber, he is holding on to it throughout the movie while they attempt to find Luke, and he happens to use it when the time seems right. And one of those times is when Kylo Ren attacks him. He dies, or loses a limb, and Rey and Chewie find him moments later.