I rode Eunorau's G20 cargo for about 20 miles on some serious hills over a few rides, and it gobbled close to 1.5 full batteries with just me (185 lbs) on it. It's a bulky bike, but you'll want such heft to safely haul you and your wife...
I'm not aware of many other reasonably priced (~$2k) mid-drive bikes with 300+lb payload capabilities (G20 = 400). And be aware that many so-called passenger bikes have limited passenger weight capacities - often well below adult averages.
Also, Eunorau sells a passenger rail and front rack kit (all or nothing), but it's a few hundred dollars more and the railing is really designed for keeping children (or a basket/crate) on the seat. It does not include butt padding.
The G20's second battery pushes its price to $2600+, but that more than doubles capacity. And professional assembly might be more than a regular bike - I've assembled dozens of ebikes "out of the box" and G20 was by far the most time-consuming.
Honestly, I believe that a "passenger" solution for you is going to require at least 33% increase in your budget... have you considered a tandem? Both riders don't have to pedal all the time.