Multi stop business trip, drive, train, fly?

[chatenoire]

I need to get from basically Lands End to London for work, the have three different stops in the Midlands and finish Newcastle way all within 5 days. Every day meeting different clients AND having to chaperone my American colleague who's visiting for said week.

So I could fly on Sunday to London and fly back from Newcastle on Saturday. (Or take the sleeper train and fly back). The only benefit from driving is the mileage (which would add to around £400 in the bank).
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I really don't want to "escort" my colleague around but the people above us haven't made up their minds and it feels rude to me to ask what's his preference. In an ideal world I don't want to go beyond our first stop in the Midlands. It just feels it will be VERY awkward.

Definitely fly the Newcastle (assuming on Tyne not under Lyme) to home leg.

Not sure what Lands End to London is like. You'll need to judge that.
Driving and train London to Mudlands is fine. You might need a hire car in the midlands depending on where the clients are.

I think I'd fly/train to London.
Train to Midlands (because I hate driving in London)
Hire car in Midlands.
Drive to Newcastle.
Drop hirecar at Airport, and fly back.

If you were to drive in your own car, would the company refund you if you broke down or needed towing off the motorway ? That’s very expensive.

I have insurance that would cover that, so that's not a problem. In any case yes, they'd pay extra as it happened before with a different car