Here are all of the prompts I requested, followed by who I asked to answer them, then what they chose. A huge thanks to everyone who helped!

Timing:

Janice678

Immediately after season 12, episode 5, The One You've Been Waiting For.

Monster:

MicheleChadwick

A small fuzzy cockapoo rescue dog named Chloe belonging to a music teacher's wife who turns out to be the cause of a spate of horrific animal attacks, because the cute fuzzy little rescue pup is actually half or full Hellhound. Extra points for hiding the reveal and Crowley finally turning up to help them track down the offending animal.

Alias and cover story:

muffinroo

Wedding planners Sam Sinatra and Dean Swift

Where they're staying:

printandpolish

Camping in an abandoned school

Location of the case:

Timelady66

Congdon's Castle, Yakima, WA (she gave me so much great info about the area I'm sure I didn't do it justice!)

Other character (OC or from the show):

Jenjoremy

Barb and Charlie from Bloody Mary (she asked for one or both)

I also ended up challenging her to give me a location and code word to include somewhere, and she said Memphis and Brussels sprouts