S0 sleep and overheating
Lets check requirements for DELL for using the only supported Sleep on its new computers.
Information about power consumption during different Standby Sleep modes here.
S0 sleep and battery
During S0 sleep your computer still uses power. And it uses significantly more power than in S3 sleep. Your CPU is active. Your disks are active. Your network hardware could be active all the time.
So what happens when you use your PC, your battery enters in critically low level, your computer enters into sleep and you connect it to adapter after few days?