Thanks so much for all your varied replies and I've only now had a chance to sit down and reply properly. I'll try and expand on / answer the various points raised where I can.
I probably should have said at the outset that this is not a delivery trip per se but a holiday as well whilst we travel. So whilst Ramsgate is doable in one hit, we would prefer to take our time. Weather is a most important consideration and with our move planned for the first week in April, the long range forecast for that week has improved a lot but still features winds stronger than we wish to venture out into.
CB18 - The boat is capable of cruising at 20-25 knots and Jenny Morgan it had a full engine and sterndrive service in November prior to being winterised with a full tank of fuel. You are so right about some boats sitting around for a year or so at the brokers.
I asked about tides in case there was a better time to approach Great Yarmouth than others. As you've all said, tide direction out at sea is a more important consideration than on the Broads so that's good to know.
I personally prefer the idea of Great Yarmouth and London Rascal has pointed out that at Berney Arms Reach there are Broads Authority moorings (I had assumed they were pub owned) - is there shore power up there as well?
I had anticipated a night to start with at Reedham and then some high speed runs over Breydon Water the following day to ensure all was well in the engine room and then an exit via GY the day after that. Another factor playing on my mind is that if something did start to go wrong out at sea, Lowestoft is not that far away.
However, Mrs Groova now likes the idea of a Lowestoft exit that some of you are plugging, especially if the weather is not brilliant, and allows us to reach the RN & S YC marina as several of you have mentioned. An escape to sea when the weather is good is then very easy, assuming they have space and a reasonable mooring booking system.
Thank you Smoggy and Stumpy, we have those books and they are both brilliant once you have left the Broads. They've helped greatly with the planning to get to Shotley or Wolverstone. DaveR thanks for your comments regarding the route to Harwich. CB18 thanks for your comments regarding the whole route to Ramsgate - we're considering an inshore route along the North Kent coast as its good to keep sight of land if possible.
So I will continue to monitor the weather closely and set our route accordingly, somewhat more wiser thanks to all your comments above.
So much to think about!