travel and subsistence, and entertaining expenses for a one man ltd company

 I am a relatively inexperienced accnt. please can someone assist me with the following.

In a one man ltd. company, the director works away from home a lot doing IT (outside IR35!) and has meals and coffees etc working long days and returning that same day say.  Can the company claim for these against corporation tax, although in the back of my mind surely he would incur such expenses if he were at home, so hence my doubts.  

I know if he's working overnight then there's no problem if the claims are reasonable.

Plus if he does a presentation in say a pub or coffee shop and buys a few sandwiches for the client(s) can he claim these or are they just entertaining (or reciprocal entertaining) and not allowable.

Don't see P11D  probs later as the company pays, not himself so he does not claim personally against the company. Many thanks if anyone can save me!