At the time of writing (before Hemlock Vale Encounter Cards are added to the database), a rough search shows that 17 treacheries attach to locations and test some skill and 21 treacheries attach to locations and have a // ability, which likely involves a skill test. Combining and eliminating duplicates and duds in both results gives us 18 treacheries that actually has "a skill test on a treachery attached to your location". Add the 2 new "attach to location and test" treacheries from Hemlock Vale (edit: there are 3 but one can usually only be tested from a connecting location) and that gives 20 valid treachery targets for Survival Technique, more or less.

As for locations, depending on search criteria anywhere from ~150 to over 450 turn up so let's just say it's more difficult to give an accurate estimation.

Notably this can boost the basic Investigate test on Searching for Izzie, but given that Jenny cannot actually use Survival Technique without advanced jank and less roundabout ways such as Flashlight (3) or commiting skill cards being available, it's more a curiosity than a legitimate answer to that weakness.

But back to the topic of treacheries from the encounter deck. Even if one may think "Sweet! Now I can get +2/+4 on my Locked Door test!" or likewise, Alter Fate (1) from the same faction takes care of most problems of similar calibre with the same one action and testlessly. So ultimately, my final verdict for the second ability on Survival Instinct is that be glad if it comes up but don't count on it to save your run.

The first ability is where the real meat is at. Being able to recycle the likes of Shrine of the Moirai and Barricade (3) is obviously very good and in the latter case potentially scenario-breaking, but I believe the best "attach to location" event that synergizes with Survival Technique is Breach the Door.

Breach the Door is a decent card that allows monster killers to help with clueing duty in 1-2 locations per game, Now Survival Technique asks: What if you can do it more than twice? Better yet, what if you can use BtD to reduce the shrouds of multiple locations to 0, multiple times per game?
Shed a Light already showed us how broken 0-shroud locations can be and it got instantly chained. But aside from that. a bunch of other cards also interact with shroud, with Lola Santiago being the most prominent example. It is a combo so amazing that it's worth building around, from the econ to repeatedly replay BtD, Farsight to play it fast, ways to tutor for both cards and whatnot.

I think two investigators in particular would want to take a long hard look at the ST-BtD combo:

• Charlie Kane. Has access to both cards and Lola Santiago. Get Bonnie Walsh in play and maybe add an Inspiring Presence to your 0-difficulty investigation test to overwork poor Ms. Santiago into giving you 3 testless clues for free per round. He could have trouble oversucceeding on the Breach test, but hey, that's what his allies are for.
• Kate Winthrop. Has access to both cards as well as Ravenous Myconid (Sentient Strain), Farsight and Barricade (3). When your location's shroud is 0, Myconid can block any non-weakness treacheries you draw even at 0 growth (because 0 shroud is equal to 0 growths and the cancel itself already changes game state). Combine with Barricade (3) to build a command center that's also a literal fortress where nobody except an Elite boss can get in. She can also stack +2s with her Flux Stabilizer to help with the oversuccess.

William Yorick, "Ashcan" Pete (normal and parallel) and Tommy Muldoon can also take this combo (edit: Daniela Reyes can too! Thanks to MrGoldbee for the catch), and could probably play it to decent effect though definitely not as spectacular. Probably involves way too many role changes to be worth it on Lola Hayes though.

I seem to be missing something about that card... Everyone says this is so good combined with the pitchfork but I don't understand why. Assume not having survival technique but the pitchfork, then you would make one attack and then need one action (where attacks of oppurtunity are possible) and you have it back. Coupled with survival technique you would spend a fast action to get it back on your hand and then spend an action to play it (paying 3 resourses). This does not help. What am I missing?