With a May birthday your child is technically 'summer born' and you can apply for her to start reception at compulsory school age, i.e. Sept 2019 when she'll be 5.
Current government has announced that they will make this a free choice for parents, rather than something that has to be applied for and granted by the LEA. Maybe by 2018, 2019 this will actually have been implemented. In which case you could, if you wanted, make sure you have moved by January 2019 and apply for a reception place for Sept 2019 along with everyone else applying for reception places. Your DD would then be one of the oldest in her year, potentially 16 months older than the youngest in her year.
If the new rule hasn't been implemented by then, you can still apply for this to happen. Each case must be decided individually, there cannot be a blanket rule. Some LEAs will grant most such applications, some will grant hardly any at all. So it would make sense to research that in advance.
You could then still make sure you have moved by January 2019, and apply for a deferred reception place. You would risk your application being rejected and your DD being made to start in Sept 2019 in Y1, in whichever school has spaces in Y1.
If you want your child to go into her 'correct' chronological year, then she would start reception in Sept 2018. You can choose to defer her starting until April 2019 at the latest, whilst keeping her place. She would then start in reception, joining children who mostly had started in September 2018. So you can apply for schools near your new home (without having moved yet, giving your old address). If a school is undersubscribed, you will get a place no matter how far away your old address is. Then defer entry until after you have moved. If all the schools you like are filled with children living closer, you will still be offered a school, can accept that place and defer entry (so don't actually have to attend), and can go on the waiting lists for the schools where you will move to. As soon as you have moved, inform all the schools and your position on the waiting lists will go up to reflect your new 'distance from school'. You can then still wait until April 2019 and hope a place comes up.
This bears the risk that you do not in the end actually move, but have failed to look for school places near where you live now.
Or you can start your child at a school near where you live now, and move her per in-year application once you move. At this age most children don't struggle much with moving schools. This will still mean you won't be able to be choosy, but will just have to take a place where there is one available. Depending on the situation where you are moving to, this can be awful, meaning long journeys to a not very good school, or it can be absolutely fine.