I've been keeping some thoughts to myself but your mention of narcotics has prompted me to say it out loud.
There is some evidence on SM sites that GP may have used cannabis (medicinal or recreational) - mentions of hemp oil, photos smoking it and in particular a mention of getting high on the photo near the coast - a great place to enjoy the weed.
It may be that when she called at the NE house she obtained some (offered to calm her down or she asked for some) and this may have been hidden from police in the original pre-arrest questioning for fear of reprimand. I'm thinking GP may have wandered down to the coast for a smoke and contemplate. A combination of the relaxing effects and existing health issue led to her "zoning out" and coming round some time later in a very cold state - the start of hypothermia and then the clothes shedding and ultimate death follow on.
It's a bit out there but I'm an ex-cannabis user and can empathise if this was the situation.
Last year, I attempted medicinal cannabis for the first time. I tried eating the raw herb first, as it doesn't get you high. It had no effect whatsoever, so I heated it in the oven, put some in a capsule and ate it. It also had no affect so I ate two more capsules. A few hours later, it hit. When eaten, the liver processes cannabis into a potent hallucinogen. It was the absolute worst experience of my life, I was completely and utterly out of my mind and truly thought I was in hell. It was a bad trip X 1000. I ended up spending the day in A&E on a drip and heart monitor, mostly unconscious and my blood pressure was 70's/30's. They say you can't overdose on cannabis but I think my experience would have killed someone with a fragile brain or heart.
Cannabis oil can refer to legal CBD oil, which doesn't get you high. It can also refer to highly concentrated hash oil, which is a class A drug, but has many medical benefits for some individuals. Many people swear by it as a magical cure.
Cannabis is known to help epilepsy in some people and in some places you can legally use medical marijuana for this reason. Gaia made some posts on social media about her mum trying to cure her epilepsy with alternative methods. I think she also mentioned herbs?
My point in this post is to agree it's entirely plausible that she could have got into difficulties after taking medical marijuana, especially if it was consumed rather than smoked/vaped. If she was having a bad trip she could have definitely ran off and taken her clothes off, as well as having hallucinations that could have got her into fights.
