Leaving 2023 Prime parked for two weeks - uncharged or charged?

It’s your call as Toyota only states’ for long periods of time’.
Personally, I would drive it down to hybrid range

 

Unless where it is at will be hot, it probably doesn't matter for just a couple weeks. The important thing will be to leave it unplugged for that time to avoid extra drain on the 12V. If it is a hot climate, a fully charged battery can be heated up to the point of entering an overcharged condition. That was part of the issue with early Leaves. In that case, use up some of the EV charge first.

I take the long periods of time in the manual to mean storing the car for a month or more. A length of time in which you would take other steps to prep the car; filling the tank, maybe adding stabilizer, airing up tires; disconnecting the 12V or putting it on a maintainer; etc. For storing Li-ion, 30% to 40% charge is recommended. Not being able to select a SOC point with the Prime, Toyota says to drain it to hybrid range.

 

Uncharged and unplugged. You may want to check the 12V battery status when you get back. See if it needs to be topped up, when you get back. If the battery gets down to around 10.5VDC, you may not be able to get it into ready mode.
If you put the 12V battery on a battery tender, before you leave, you won't have to worry about it.

Hope this helps...

 

Ideal PHEV-battery storage SOC is around 25%.

Definitely don't leave it above 50%.

Also, if you have deeply depleted the HEV reserve and you are well below 0%, that could be bad for storing the battery, too. That's why the owner's manual instructs to run the ICE until it stops under such conditions. Or simply plug it in and charge it to the ideal 25%.