You just jogged a memory.
There is an abandoned hotel on I-65 at Indiana 43, which is at the I-65 exit for Battle Ground, IN. Former Holiday Inn/Days Inn. It's in horrible shape but I guess it would beat sleeping under a bridge. Or provide shelter for a drifter taking odd jobs. It's about 6 miles from West Lafayette where a lot of construction has been going on and was last winter. A judge had ordered it torn down in October 2016, he gave them 60 days. But I found another article from May 2017 that said an investment company purchased it. So it would've still been standing in February this year. You can see photos and video of the interior at jconline link. (If you can't access JCOnline I've included a second link, article only, from Journal Gazette.)
By car, it's about about 17 miles from the hotel to Monon High Bridge. I also looked for RR tracks. There is a set of tracks a few miles south of the hotel that go directly into Delphi and on to High Bridge area. Don't know if they're active tracks, but walking them would offer more privacy than a road, though several hours easy on foot. Tracks are directly adjacent to Hoosier Heartland Highway in many spots. Someone staying at the old hotel would have to walk 3 miles south on I-65 to just south of Indiana Route 25 (HH Hwy), pick up the tracks and follow them northeast through Delphi and they'd end up right at the High Bridge. Back roads could be used to reach the tracks too but choices are fewer due to needing a bridge to cross the Wabash River. I included some maps below but had to break them up so RR tracks are visible.
http://www.jconline.com/story/news/2016/10/04/judge-gives-60-days-raze-notorious--65-hotel/91449790/
http://www.journalgazette.net/news/...r-owners-to-raze-Battle-Ground-hotel-15625601
https://www.usnews.com/news/best-st...s-plans-for-i-65-eyesore-hotel-near-lafayette
Aerial of abandoned hotel:
Road map abandoned hotel to Delphi:
Yellow arrows point to hotel location in Battle Ground and RR Tracks south of motel heading to Colburn, IN
More of the RR tracks continuing from Colburn to Delphi
Close up of tracks through Delphi to Monon High Bridge