If you simply want to supply for guests and maybe one if any air conditioner, you don’t need to go as far as 50 amp. When our house was built I had a simple 30 added to the side patio/RV pad area on the house. It’s done the job and a plain 15/30 adapter makes it handy for other purposes. It’s on its own breaker in the Main in the garage, as is the 30a welder.
If you expect, on the other hand, guests staying out there on very hot summer nights where 2 AC’s would keep them more comfortable, then spend the extra bucks on the extra service (240v?).
Joel