On purely economic grounds one could argue that delaying the Annual (to the end of any grounded time) is worth doing because it stretches the money you paid for the last Annual that bit more
You can also get an insurance refund/credit for the grounded time; they will reduce the cover to ground risk only. I've just got a £500 credit due to my engine being out for a bit, not bad.
OTOH it is much better to schedule one's Annual in the middle of the crappiest weather the UK can deliver which is normally Dec-Feb
We often get a nice April/May.
I would do the Annual NOW. Ultimately it depends on the value you attach to downtime. An Annual in the summer can drive you bonkers.