I was completing an IFR flight tonight from KBNG to KIZA (both are non-towered airports), and had been cleared to change frequencies to the CTAF freq. I advised the approach controller that I would cancel IFR on the ground after landing. Then it got interesting... I lost my PFD just before the FAF on the GPS-A approach. I kept my composure OK as my backup VOR/HSI was operational and altimeter was fine. Conditions were VFR with the runway in sight. Then while on the last 1/2 mile of final, another (drone) aircraft who was not on the CTAF frequency pulled right onto the runway and proceeded to take-off in front and beneath me, as I overtook him. I powered up /pulled up and aborted the landing.
I know this is a real-world scenario that occurs, but I was definitely glad that this time it was from the safety and comfort of my home.
I announced on the CTAF that I was going around left traffic and landed relatively uneventfully the second time around, though I used up 100% of the runway. (actually about 105%

)
I later wondered, that since I had been cleared on the GPS-A approach before changing to the CTAF and had
not cancelled my IFR flight plan in the air, if I was wrong to go-around instead of flying the published missed approach? Should I have started the published missed and re-contacted Approach with my intentions and received a new clearance?
Don