Hi Liz,
I have never done The festive Germany Trip, But I have a friend that has, And they do recomend it, As for stopping off at the chocolate factory I am assuming you mean AJs if i recall rightly. I have been on 8 coach trips and I think nearly all of them, have stopped off there on route back to the Ferry port. Also most of the coach drivers get discounts etc as they have loyalty type cards, where they a mass points. So the chances are you will stop there.To get your chocolate fix lol, And the cynical side of me says it is more for their benefit than ours.
I think it would be good to try a flight holiday. I have just returned from Austria, This in now my 4th flight holiday. I managed to get a connecting flight from Glasgow to Gatwick to catch my tour flight. I can reccomend The Austrian Lakes a great place to start, your first air holiday. Its only a couple of hours via plane, including your connecting flight if required. Which you can have arranged via Just You at very good prices. Its is as cheap driving & parking , Or even to go via rail or coach or stop overnight ,and it is a lot less hassle.
Have a great Christmas
Andy