Around here lamp-posts generally get supplied in at east 6mm² if not 10mm² or 16mm² (for probably a mix of reasons including mechanical robustness, fault protection reasons and convenience of connection to the larger mains cables). I doubt anything smaller was used for the cabinets, so cable size is unlikely to be an issue. A fuse upgrade if needed wouldn't be the end of the world.  I suspect most will be single phase though, which is OK for a 7kW charger, but I suspect most cars will want 3-phase for 22kW, which might be more of an issue.

The biggest problem I see though, is that all the cabinets around here are located at the back of the pavement - so I don't see how anyone could plug in an EV without running the lead across the pavement - which isn't permitted. They have to be moved, the re-using the old cabinet isn't really much of an advantage.

   - Andy.

Around here lamp-posts generally get supplied in at east 6mm² if not 10mm² or 16mm² (for probably a mix of reasons including mechanical robustness, fault protection reasons and convenience of connection to the larger mains cables). I doubt anything smaller was used for the cabinets, so cable size is unlikely to be an issue. A fuse upgrade if needed wouldn't be the end of the world.  I suspect most will be single phase though, which is OK for a 7kW charger, but I suspect most cars will want 3-phase for 22kW, which might be more of an issue.

The biggest problem I see though, is that all the cabinets around here are located at the back of the pavement - so I don't see how anyone could plug in an EV without running the lead across the pavement - which isn't permitted. They have to be moved, the re-using the old cabinet isn't really much of an advantage.

   - Andy.

Many of the green cabinets I can think of are also on road junctions.  Not the places you want people to be parking up to charge their cars.

I'm not aware of any car that can charge at 22kW single phase.  It's usually 3.6 or 7.2kW single phase, or else 11 or 22kW three phase.  A lot of cars can't actually charge at 22kW on AC, as they have been optimised for DC charging.