I'm new here, and so hope you'll bear with me. I admire the site very much, but acknowledge that I bring a certain bias. I worked at a shelter for Domestic Violence victims and volunteered on their hotline after I resigned the job (stress).
As previous posters have noted, my alarm bells are ringing at some of the fiance's statements. Not implying he did anything, but perhaps isn't telling the whole story. When I see a significant other on TV & the missing person's character is tarnished (or trashed) the bells go off. When the significant other transfers sympathy to themselves (illness or whatever), the bells go off.
Two phone calls to him at 4:15pm to say she's leaving? Weird. His meeting breaks up 15 minutes later, although expected to go on for 2 hours? Weird. He expected to "meet her on the road"? Why? Why didn't he go home & get his own phone charger?
Both cell phones aren't functional - she forgot hers & his battery is almost dead. He stopped for 2 hours for "a repair"? Yet she managed to call him & give him directions? More bells. Why did he set off for Castle Rock if he didn't know the address?
The wine in the photo posted by another WSer seems to have the kind of cork you can pop off with your fingers. It could have been a "hostess" gift, although obviously not if the bottle is half empty. The fiance said she was on meds for anxiety, so I suppose a drug interaction was also possible. However, if she were that impaired I'm amazed she negotiated her way around all those hours & down that road.
The van was borrowed from her fiance, and the keys were left on the dashboard? Weird. No one packed a suitcase for a weekend trip? Perhaps it simply hasn't been found yet. Has anyone verified that the fiance was somewhere repairing something for 2 hours?
To me, absent a serious medical condition, SS seems to have been avoiding the stepfather's house AND her grandparent's house. Why? Yet why drive around in circles for hours?