Although you need to inspect for additional damage under the bumper, the cover itself shouldn't be a major problem. I have had great luck with using a heat gun to remove the dents in a bumper cover. I would remove the bumper cover from the car for this procedure - there are probably YouTube videos detailing the removal. Additionally, removing the bumper cover would allow you to easily inspect for additional damage that may be hidden while the cover is on.
You should be able to find the taillight assembly used on eBay or Amazon for not too much money (1995-1997 DODGE INTREPID LEFT DRIVER SIDE TAIL LIGHT LAMP OEM, 166-01477 | eBay
, Dodge INTREPID 1995 1996 1997 TAIL LIGHT Lamp Driver Left LH Side OEM Genuine | eBay
, 93-97 DODGE INTREPID LH L LEFT HAND DRIVER SIDE LOWER TAIL LIGHT BODY FILLER OEM | eBay
(the taillight assembly is actually two pieces - you might be able to get away with just this piece)). Additionally, there are two UPull locations near me, and I'm on the notification list if any of them are brought into the locations. I could keep an eye out for one, if you'd like me to.
As for the rest of the Intrepid, I have a 3.5L engine with more than 307,000 miles on it. The only non-maintenance work on it has been replacing a leaking camshaft seal (some time prior to 200,000 miles) and replacing a bad head gasket at about 286,000 miles. I've really liked and enjoy this car. I've never owned one that I liked better. I'm hoping that I die before the car does (and hope that parts, which are somewhat hard to come by these days, remain available).
I noticed on the report that you linked that the car was sold for $300. Were you the buyer?