Hipertextual on the 3rd season of Black Mirror
The end of the San Junipero episode can be interpreted as happy and positive, in favor of love and others, but we don't think that was Charlie Brooker's intention. We see Kelly and Yorkie driving happily toward the horizon, but it is impossible that those two are Kelly and Yorkie.
Human consciousness is an extremely complex phenomenon, thoroughly studied by philosophers and scientists alike. What happens in San Junipero takes us back to the famous question of "are people brains? Can subjective experiences of reality be reduced to simple electrical impulses? Well, we can't safely answer any of those questions. But, after a few minutes of logical reflection, the answer to both seems to be a resounding no.
Philosophers like Martin Heidegger have studied the phenomenon of consciousness, trying to discover how it is generated and how it allows us to perceive what surrounds us. More recently, neurologist Raymond Tallis has outlined a possible answer to this.