Your option 2 is best, but having said that, rescue crews will want to know you're out there sooner than later.
In the option 1 you described, you would be activating your PLB, then waiting for rescue above the treeline. Fire doesn't go very far above treeline, but smoke, ash, embers and heat do. Just because you're above the treeline doesn't mean you're guaranteed to be safe from the fire, you just won't likely get burned to death, but death by flames isn't the only way to die in a forest fire.
When the Kenow wildfire burned 38,000 hectares of forest last summer, the ash from the fire was piling up in my back yard 50km away. Air quality was so bad that we had to stay indoors with all the windows closed, and the sun was blotted out for weeks. If you are on a mountain directly above a blazing forest fire, your odds of dying from smoke inhalation are pretty good, but breathing in a hot breath of superheated air is what usually kills people trapped by fire.
The situation you described is the exact reason why parks require people to buy backcountry permits to go backcountry camping. Park staff need to have a record of how many people are deep in the backcountry, so they know in a situation like a forest fire how many people they need to evacuate. If you're going to a spot where they don't require permits, then make sure someone knows where you are, or at the very least leave a note on your vehicle indicating where you have gone and when you expect to return.
If you are in the backcountry and discover a fire, you must report it immediately, especially if you are above the fire and it has you cut off from your escape route. You're best chance of surviving a fire is to reatreat! If you are on top of a mountain, this means getting off the mountain. Do not hang out on the rock and expect you're going to be safe, you need to get off that mountain as fast as you can, if you know of an alternate route, take it. Rations are the least of your concerns when running from a wildfire. You can survive days without food and water, but you will not survive breathing in unrelenting plumes of smoke or superheated air. (One caution with descending a mountain is to choose your route wisely; if you get ledged-out on the decent you can get yourself in just about as much trouble as being stuck in the path of a fire.)
In any case, your first course of action should be to call for help, if you have no means of contacting Emergency Crews, and no way to evade the fire, then use your PLB. Rescue crews will want to know that you are out there. The problem with using your PLB is that once you deploy it you typically need to hang around in one spot in order for rescue crews to find you. If you're in the smoke however, it's unlikely they will ever find you, so deploying it is not going to help you get found unless you can get out of the smoke to somewhere open and visible.