There is no hard and fast rule here. I managed to increase my FTP from 277 W to 309 W after mid-volume SSB1+2. However, I can already tell that the next 30 W will be much harder to come by. Those near FTP efforts during SSB1 felt really easy (since my FTP was increasing and effectively, I was doing them at a lower level). The closer you get to your theoretical max, the harder you have to work for those gains.
But there is no hard-and-fast rule how quickly one individual will respond to training. Also, you didn’t mention your weight, so depending on how many kilos you have left to shed, you could also increase your specific power (W/kg) while keeping absolute power (your FTP) relatively stable.
Personally, I would try and avoid setting yourself goals that you can’t influence. I don’t think it is smart to set myself the goal to e. g. increase my FTP to 340 W by this time next year. What I can do, though, are things like “complete this training plan”, “invest time in improving my bike handling”, “race my first crit” or “shed 2 kg”. These are all things under my control.
Also, I would caution you to do a high volume plan: as the guys emphasize time and again on the TR podcast, consistency trumps volume. And you may not know how your body reacts to the increase in training volume.