Have done plenty of long over water in singles myself and don't really see any particular issues with this one. Just like anything it's a matter of thinking about the possibilities for things to go wrong and being prepared which it seems like you've already done in regards to Accom, Fuel, Liferaft etc...
Be flexible with your departure dates, you'll want good weather no doubt so you can enjoy it without having to break a sweat, get some travel insurance if you can incase you need to change accommodation at either end, it might be covered with the right insurance which will put your mind at ease and take away the "Need" to get going.
Keep the life raft upfront with you of course, wouldn't be the first one to stick it up the back which could make it difficult to grab in an emergency, also have a good read through the instructions, what's inside the kit? Do you know how to use the pyrotechnics etc..? I'm lucky enough that my company has gotten us practice liferafts in the past to chuck in the pool with us and actually have a play with and it's not as straight forward as you might imagine when it comes to where the provisions are stored in it.
One thing I'd point out is making sure your HF is good quality, a lot of people have one they rarely ever use and when they finally do need to are shocked to find it's pretty useless!! Double check your frequencies you'll need along the way are available on your HF if it utilises crystals, if not these can take a few weeks to be made up. Think about hiring a satphone for the trip as well, always pays to be extra cautious incase something fails and they aren't overly expensive to hire for a little while.
Check your ELT as well, I've had plenty over the years that get everything except the damned switch inside the cockpit checked and that switch is often completely jammed and unusable! Check the instructions for manually testing it and do it at 0000 UTC if I remember correctly, this is the time advised for testing ELTs (Someone can probably correct me on that though?).
Last piece of advise is to take some Travel Johns, they aren't glamorous but if you're taking the wife and kid/s with you for a few hours with nothing to look at but water...well, you'll be glad you did! haha.