No water for for more then a couple of hours on a routine basis is not acceptable to me.
Hay wise, my long time barn threw hay at 6am, noon, 6pm and at nite check, typically 10pm. Amount as needed needed by each individual horse. Priced accordingly. Retirement barn they were given a small flake with grain and meds at 6am, out on grass 8am to 4pm and had hay in the stalls at 4 , more added at nite check, 8pm if needed. Winter was hay at 6, noon and 6. Again at nite check if needed.
When I couldn’t afford that type barn, they fed twice a day and not all of them had any grass turnouts. Honestly never had any problems but never picked a barn that shorted the amount of hay they fed each horse or used a one size fits all limit. At times I added my own soaked cubes on days I rode but that was only in barns I did not pick for long term boarding, Because sometimes you have to settle for what you can get at the time until you can get space elsewhere…but it better be priced accordingly.
Boarding is always a compromise. Even keeping at home involves some flexibility.