He's probably waking up early because he sleeps all day long.
The thirsty thing unfortunately sounds familiar. Is his urine yellow or clear? Is it concentrated at all? Loki has diabetes insipidus which causes increased thirst because his body does not concentrate urine. It's easy to rule out though. He also might not drink during the day because you are gone. Mine don't eat when I'm gone. If I give them a Kong and leave they don't really eat it until I get back.
You really should consider a dog walker. He's going to get pretty bored all by himself all day and a bored dog can be trouble
