Oh, Blood Fever is so fun!

I imagine they both stayed in Starfleet and pursued endavors related to their passions: Tom something related to piloting and/or maybe building new ships. B'Elanna also always enjoyed the challenge of unknown tech (like the time she fixed that robot or the warhead), so I can also see her going into a field related to that. Alternatively, I see Tom going full dad and taking care of their kid(s) while B'Elanna pursues her career. That's just my vision for them, of course. I'd love an actual update on them.

Tom would love the excuse to play all day. It would be interesting to see what kind of holodeck programmes he would come up with to entertain his child.