Standard Procedure for Stage 1 OPSCC P16+?

I can’t give you medical advice. Excessive? Not really considering you had lymph node involvement. Of course your tonsil is also a lymph node as well.
You may not finish your course of radiation. You may not be able to tolerate it. However most people do finish with a little prodding and persuasion.
We are all different and all of our treatments are often as unique as we are. Your oncologist(s) take a lot of factors into the equation to calculate what dosage you will need. True, it often over-cooks us but the chance of a repeat tour of the radiation vault is very slim. Undercooked, we likely will be asked for a repeat in a few months to years, which would be a far more difficult experience.
I know you are concerned, nervous, a bit frightened perhaps. The next few months will not be pleasant. This will be a life changing experience you did not seek but you will be able to reflect on it in the years to come. It will require courage, improvisation, questions, and for many of us, prayers.
Will you keep me posted as to your progress? Courage.

My case was extremely similar to yours. TORS for base of tongue tumor. Also neck dissection. 2/25 lymph nodes positive. Primary tumor had clean margins. 60 GY on the positive side of neck. 54 Gy on the other side. Also 60 Gy to tumor bed inside throat. I had Proton instead of Photon radiation. I feel Proton is much more targeted with less side future sides effects. I have read alot about deescalation treatment with early stage SCC throat cancer. I think the trend is going that way. However, Your team of doctors probably know your best treatment options. It is a tough battle for several months but you will get through it. After about 16 months since TORS and 12 months out of radiation I would say I am about 90% back. Good luck and have Faith.

One thing I am finding out is this big de-escalation cancer treatments especially with radiation coming about for people who got it as a result of HPV. In 2008 I was officially Stage IVB T2N3M0 on left tonsil caused by HPV and one of my 3 infected lymph nodes. I had 35 rounds (7 weeks) of Photon radiation which amounted to 70 Gy and 3 rounds of the platinum-based chemo Cisplatin. I also attached four articles on the de-escalation here.

You will get better. Hope this helps. Good luck.