(I read plenty of cases on Websleuths, but don't post much, so this is my first time weighing in on this one. So, hi!)
This has probably been discussed and I missed it, but, if Elizabeth told her sister to call the police if she wasn't home by 6pm, what triggered her family, friend, whomever did it, to report her missing at 12:41pm? Was it that she hadn't shown up at school and no one could locate her elsewhere?
Also, maybe I'm naive, but my thoughts on the teen marriage search is that TC was looking for if, and where, he could legally marry her without another person's (parent's, judicial) permission, if he were "free and clear" of his current wife. Since the answer was nowhere (in the US) + divorces take time, real marriage just wasn't going to happen. Or perhaps he was searching for countries where they wouldn't have problems. What I find interesting, is prior to March 5 (the day he conducted the search), Elizabeth had no real mention of marriage on her Instagram. But on March 5, she had 2 posts directly referencing it, plus a promise ring post. And then several more in the days following. His first post that seemed to hint at running away was on February 23, with a picture of a jeep at the ocean with his the hashtag #ohtheplaces he then used on all his later (and very frequent) destination posts. That day also happens to be the day ET posted the Roses are red poem...
Perhaps this whole running away bit was originally construed by TC just for TC, and ET jumped on board and ran with it and he figured why not? TC's life had basically fallen apart (his own doing), why not run? Who knows how his wife reacted to this investigation and suspension and what their interactions were while he was still around...It's obvious based on TC's Instagram that as of February 23, he was planning to run. It's interesting that all his #ohtheplaces posts on February 23 didn't include the #love hashtag as well. But from the first one on February 24, and all subsequent ones after, both hashtags were used. Read ET's posts from early on February 23...they seem to indicate "trouble in paradise". Then February 24, he starts tagging his exotic photos #ohtheplaces #love and she posts her first travel themed post with a caption mentioning @bestfriend. My theory? TC was planning to run, and decided to do so on February 23. Sometime later that day/that night, TC and ET concocted the plan for ET to join him. And they just spent the next 20 days figuring out how to do it.
On the possibility that they're hiding in a storage facility. I don't think they are, but I think the Nissan Rogue is, and they have another vehicle. As someone who's done lots of searches for enclosed vehicle storage (I have an RV), there are hoards of spaces--in cities, in remote areas, in well maintained facilities, in crapholes where no one investigates anything as long as you pay your rent--where you could easily store a vehicle. No one said, to my knowledge, they were spotted in Decatur in the Nissan Rogue? Maybe it took them so long to get there/be sited there because they stayed in the immediate area switching out vehicles and stocking up from the stockpile of supplies they accumulated during 20 days of planning. And maybe they went to Decatur to throw people off, and then came right back and are hiding out "in plain sight", not far from where they started.
On another note, they could definitely be in a National Forest or the like campground and no one would know the better. Many are first-come, first-serve, have no one checking you in (you register yourself and pay, no ID needed), have water and electricity at the site and bathhouses (hello hot showers) mere steps away. Many are in areas not near big cities, and I could definitely see them popping in to a general store and buying supplies and no one thinking anything of it. Especially if only one went. It'd be pretty easy to survive in such an area and not feel so rugged in doing so.
