I too agree that it is best to take care of it all at once, rather than risk having to put your body through it a 2nd time.....Actually I think the protocol (with most Drs) is that if they found cancer in one lobe they remove the entire thing.
If it was me, I would tell the surgeon if they find cancer, to remove the whole thing. If it is just one side that you have problems with, then remove just that lobe. Just my opinion of course. :)
I had a friend who had the same cancer and had a partial - later the cancer came back, and she had to have the other side out and have all the same treatments again. She was upset that she did not have a total the first time.
I think the full is more prudent. The nodule is large. You can talk to your doctor but he is making the determination for you, not your family, and for the best outcome for your health based on your case. If you have questions, talk to your doctor, not your family.