My logic (rationalization ?)
with the Durango was --- rather than stick with the 6 year old one (even tho it was in great shape/low miles), get the '23 and reset the clock. There won't be another opportunity to get something like this and I hate, hate, hate what's coming. I plan to keep it until the wheels fall off or they take my license away.
Your '18 will bring good $$, so sell it and grab the new one while you can !