In addition to providing some day places, some residential and nursing homes also offer "short stays". This can be for just one day / night or could be for a few weeks. Depending on the circumstances, this may be on a one-off basis or as a regular planned break.
Private Homes earn their income by having their beds full. Therefore, many homes will only offer a short-term break if they happen to have a vacancy at a particular time and so these breaks cannot be booked in advance. For this reason, most planned short-term breaks take place in homes run by the Local Authority's Social Services department. Many such homes have "short stay" or "respite" beds which are only used for this purpose, and so they can be booked in advance. Because of demand, you may need to book early if you want a particular period of time.
Whilst personal arrangements can be made with the private homes, often respite care is arranged through social services, regardless of where the short-term break is taking place. Here is further information about residential / nursing care. This is to help you think about choosing a permanent home but none-the-less has lots of helpful information which you may find helpful, such as, what it may cost, the standards you can expect and contact details for your local social services.
For social services to be involved in any arrangements, the cared-for person would have had an assessment and have met the eligibility criteria
(45KB - pdf help). Any financial contribution towards the costs would be determined by the charging criteria.
Contact your local social services office.