I'm curious, how much did they offer? Vs How much you paid?
As for the depreciation, when doing the calculation first you have to subtract any delivery fee and federal/state EV incentives that were available from the price that you paid. Once you have that number, most car brands will depreciate about 25% after the first year.
From my experience the EV cars depreciate a little faster than ICE cars, I've had it explained to me that an EV is like driving your new I-Phone. In your case you have the 90D, so think of it as an I-Phone 6, the P90D would be the 6 Plus model, the 100D would be the I-Phone 7. When the new phone comes out, your "old" phone is now worth a lot less.
Looking at the CPO's 90D, someone can buy a 2015 for $71,000 with about your miles, or can buy a 2016 with half your miles for $82,500, so if your going to do the trade, do so before it drops even more.
Just my two cents, anyone have any other thoughts?