Can you not fit a standard "bathroom extractor" in the kitchen? Again, with an over-run timer. Any extractor is better than no extractor.
I will re-iterate that unless you solve the problem of too much water vapour being produced in the house (and it not being removed from the property), installing cavity wall insulation or replacing the glass could make the issue worse and more pronounced in other areas.
The condensation is caused by the tenants, not the lack of insulation and/or age of windows.
I have single glazed leaded light windows in my house. They get very cold to touch. They should be far more prone to condensation than your walls and windows.....but....I get none (or very little)....why? Because I ensure moisture is removed from moisture prone areas, I do not dry clothes on radiators, I keep a comfortable warm consistent temperature rather than extremes of hot and cold.
What my windows do show at times is how quickly a lack of ventilation can result in condensation. If I start cooking, and do not put the extractor on, and the heating happens to be off (if cold outside). The windows at the other end of the house will start to get condensation on them. That is how quickly water vapour can build up, dissipate though the house and condensate on a cold surface.
Now imagine your house....tenants cooking without an extractor, drying clothes on radiators and not heating the property properly. They are literally walking around the house and emptying a bucket of water in each room (or boiling it away). If that water can't escape, it just stays in the house and comes back as condensation. That is how you have to picture the situation.
That is why new glazing and cavity insulation will not solve the issue. The tenants will still be walking around emptying buckets of water in each room.
Good luck and happy new year.