You could remain in these bodies indefinitely if you would allow your environment to continue to produce new, continuing, life-summoning desire. You could be one who opened your vortex to continually find new things to want, and those desires would continue to summon Life Force through you: you are living raucously, you are living joyously, you are living rambunctiously, you are living passionately… And then, from that same framework — you make a conscious decision to make your transition.