I've just had one of those weird nights in that I've been fine during the day but as soon as I lay down in bed I got that feeling that says 'Beware AF'. I lay awake until about 3am doing deep breathing but I lay absolutely still because I felt the slightest movement could set off an episode. I eventually got up and went and sat on the toilet. This really works for me and all the symptoms seem to diminish when I do it. One bit of advice for anybody getting up in the middle of the night. Always take in deep breaths (inhale deeply) while you do exertions such as getting out of bed and getting off the toilet. I find it works a treat and stops AF from starting as happened to me on a couple of occasions a couple of years ago when I exerted myself having just got up.
Still didn't feel 100% when I got back to bed, but definitely an improvement which meant I finally went to sleep and felt fine on waking up. Lying in different positions definitely affected my feeling of vulnerability to an episode which just further makes me believer this is vagal/vagus initiated.
Not asking a question or expecting a response to this, it's really just a 'diary' entry that others may be able to associate with and shows that you can hold the episode off if you remain calm and take the necessary steps to alleviate the situation. A episode does not have to start when you feel it wants to.