Given that you are separated it seems the house of cards is already falling.
Your story is very similar to mine. We have been separated a year but he lives by himself. Recently I found out via the police his drivers license was suspended and he was picked up for driving suspended but he continues to drive around anyway. He has no idea I know. I don’t feel like I know him anymore. Gradually health stuff is happening too like blood pressure problems and gastrointestinal problems despite keeping himself reasonably fit. Maybe there is other things he’s not telling me. Somehow he seems to maintain the work he has but then again if he lost a job he probably wouldn’t tell me anyway! Lying goes a long with the territory unfortunately so it’s hard to gauge exactly how bad things really are. I have noticed cognitive changes though like forgetfulness.
I have to say all this is much more bearable not being under the same roof. I feel much more detached from the chaos. All the best.