It would depend on how badly the side windows were rendered opaque. If the Capt's side window still had enough clarity to make out the runway boundary during the roundout and flare, that would be enough.
You can land airplanes fine without being able to see directly forward as long as you can see out the sides. When you fly a taildragger from the back seat, which is normal in taildraggers you solo from the back, like J-3 Cubs and most biplanes, you land all the time without being able to see a damn thing in front of you since the nose blocks everything about 60 degrees each side of the nose and you land using your peripheral vision. So that's not really a problem for a decently skilled captain.
If the side windows were as opaque as the windshield, you have a problem and you'd have to try to whatever you can think of. I'd go try to find some cloud and see if I can get enough moisture on the glass for the wipers to work. Or whatever off the wall ideas any of my crew can think of.
And if none of that works, well you do the best you can, performing your own homebrew Cat IIIB landing and hope you can stay between the runway lights. You can just stay on the localizer right down to the fare and control the flare based on rad alt, so the really big challenge is really just staying centered on the runway. You might try having a crew member sit behind you against the rear side window if that had visibility, where they can see the runway edges, and verbally call out left/right corrections through the touchdown and rollout.
If it was late enough in the day I would probably elect to delay landing until dusk because the runway lights would show up way better though the frosted glass effect in the dark, well enough at least to be able to stay between them. I would say that as long as you can make out the runway lights, you'd be good.
Even during the day, depending on how bright the day was with cloud conditions etc, you might find the runway lights cranked up to max intensity could be made out through the goo, good enough to be able to land and stay on the runway. So I don't think the bug mooshed windows are a death sentence, but you'd be earning your 6 figure salary for sure.