I recently sold my company and retired to live the good life. trying to not be the "kid in the candy store" when it comes to hobbying. since money or attachments (wife or kids) is not a problem, I have been meeting with providers once a week . How much is too much?
... it'll be too much when you say to yourself, "I think it's getting to be too much."
You retired to live the good life, right? So do it!
I am a man of rather large appetites. Personally I don't seen anything at all wrong with a different woman every day. I don't have the appetite I used to have, but it wasn't that long ago that I would see 3-4 different women each week while at home and then once or twice a month take a long weekend somewhere in Latin America and see a dozen women in about three days. Even at my "advanced age" now, I still try to do the same except I no longer even try to fuck a dozen women in a weekend. Getting old sucks, but it beats the hell out of the alternative.
Some people get burnt out on this, I saw my first hooker 42 years ago and I am still going strong.
It's different for everyone. Too much for me is 3 times a week. I do too much as often as possible
otherwise, who's to say?
If time and money are no object, then your own physical ability is next.
Caveat: Like anything, if it gets in the way of truly important things it's too much. If you're just doing it out of habit/ritual, it's too much.
I do have time and financial limitations, but once, and sometimes twice a wek is not too much for me
If you dine out every night it does start to lose some of the novelty
Unless you love oral as much as I ... the only aspect of my life where I might invoke the gluttony mulligan. If declined, I'll dine until I find the hole ...
1) you spend more than you can afford to
Or
2) you get tired of it.
...you start spending the grocery money and mortgage on it. Then it might be a time to reassess and pull back 
For the short-term immediate future enjoy it as far as your desire and capacity allow you.
Then sooner than later think about long term plan. How is your health? how old do you think you may live to? the money may seem endless at this point but it only takes a major illness/operation or two to wipe out a lot of your saving. Or for that matter another recession or two.
OTH you maybe the type who just wants to live it up and don't mind growing old penniless, destitute and living under a bridge 20 or 30 years from now, LOL
With a strong net worth and $0 mortgage.......still somewhat conservative by nature.....so 3-4 x per month, but sometimes 2x per week. Still self employed and middle aged so why retire! I realize an illness could set me back and 10 years ago I purchased a Long term care policy, in order to hedge my assets should something unfortunate happen to me. Most insurance agents suggested I wait awhile, but the premiums were so low so I opted in at age 39.
The pawn shop.
Or your dick falls off.
Whichever occurs first
If I had unlimited money I'd probably do 3x a week for about 4 hours each time
8 years ago with one one-hour session a week for the six months, but became addicted to the endorphins. The more I hobbied, the more I wanted. Now I do three sessions a week, divided between one hour with a new girl, and two 2-hour sessions with regulars. Its the perfect balance for me. Like you, no wife or kids at home, so I don't have to worry about anything else except my business.
To keep track of this, you would need to subscribe to my "happy visit information service." For a few years my frequency was none because I was back in love. More recently I have been managing a really busy practice and it is not centrally located and I am old so my frequency is much lower than I would like. As you see you would really need to subscribe.
You can do so by signing on to Born Yesterday.com.
Seriously, if I were as free of constraints as you, even at my age (mid 70s) I would be seeing people very often controlled only by my wants and the availability of attractive or interesting ladies. There are tons in and around Philly and many great visitors.
It's the good life to be free and explore the unknown (Until it’s not fun anymore or maybe health issues…?)
And do a 90 minute or 2 hour session. Helps me look forward to something fun every month
You'll never do it any younger!
while you are younger. Sooner or later your appetite will lessen and your equipment will not work as well either.