Blindsight or Tremorsense are the only abilities that let you 'see' through fog or smoke.
I'll spare you my original overly-off-topic explanation; suffice to say that according to the rules of visibility in 5E, when something is blocked by something else, there is nothing anyone can do to see through it except for possess the above abilities. You are 'blinded' by the object that is blocking you, and until that thing that is blocking you is removed, you will always be 'blinded' by it.
Tremorsense and Blindsight are the two things that RAW let you detect the location of things without having to see them, and as such these are the two RAW things that would let you look through heavy smoke. Neither is available as a class ability, so your PCs are not likely to have access to them.
As you mention, Blindsense does not let you see through smoke, because Blindsense only works when the person you're looking for is hidden (took the hide action) or invisible (had invisibility cast on them).
Starting at 14th level, if you are able to hear, you are
aware of the location of any hidden or invisible creature
within 10 feet of you.
If you're just standing in a fog cloud, then someone with Blindsense cannot detect you any better than someone without Blindsense.
If you're worried about a smoky room, you can look at the spell Fog Cloud to see other ways to get around it, mainly:
[the fog cloud] lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.
So, it looks like RAW, mild to moderate winds can disperse fog/smoke to a degree that it stops interfering with vision. In that case, if one of your PCs has a spell that generates wind, then by the Fog Cloud rules they could use it to disperse the smoke and see through it.
They could also have the party barbarian tie large paper fans to his arms and flap them like the dickens, but that may or may not be too silly for your campaign.