How long can a year old tortoise be left alone?

I have a year old Horsfield tortoise who is kept indoors. I am going to stay with my Grandmother for a few days (leaving tonight and coming back on Friday morning – 2.5 days) and I was planning on taking him with me. However, I am worried about transporting him incase the travelling causes him stress.

Although he is fed every day, he always has some left over when I go to feed him the next day which leads me to think that he probably doesn’t need fresh food every day. Because of this, I figured, if I leave enough food he’ll probably make it last.

He has a heat lamp and UV light which I would leave on to stop him getting cold (even though it is fairly warm in my house).

I don’t have a spare key to leave with someone to come and check on him so my choices are, take him or leave him. I am happy to do whichever is best for him.