Water alone is a very poor conductor of electricity, especially at the volts and amps from an EV charger. Also, the port is well protected and, in a sense, not directly connected to the high amperage battery packs. The AC voltage and current goes through an inverter that converts it into the proper DC voltage and current. In other words, you can’t get the high DC amps at the charging port. There is also a few fail safes that protect you and the system. The manufacturer would advise against it but they do so to protect them selves in case there is a malfunction or a broken defective charger plug or cord.
Can you? Sure. Go crazy. Low chance of realistic hazards.
Should you? I mean... hell, one single commute simply without speeding would save you as much energy as you'd charge during that time. IMO it's a waste of effort to set-up and take-down.
I'd also be a bit sus about the integrity of the outlet there. Any time you plug something in, take note of how it felt to push the plug in. If it's loose and floppy and comes back out of the outlet a little, that's a BAD connection (will get hot/burn something). If it feels somewhat strong/tight, it's probably good! But those outdoor outlets tend to fall in the bad category...