Hello and welcome to HCM.
Thank you for your query.
Before even considering the size of your father's prostate, we will almost always have to consider a conservative method of management. This will include medication. Your father's prostate is indeed not that large, and unless it is producing significant amount of trouble, it should be treated conservatively. This will include alpha blockers and 5 alpha reductase inhibitors.
Only if the medication is not effective in reducing the size of the prostate or if the
enlarged prostate is causing some amount of discomfort should surgery be considered. TURP is indeed the best option if surgery has to be considered.
The medications should start taking effect soon, and will show results within 2-3 months. As mentioned by you,
hernia is not an emergency, and thus, I don't see why your doctor cannot wait for a while if he considers the prostate to be a problem.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you.
Best wishes.