Specific arrangements vary between productions, but rehearsals are usually in London, and children usually travel with chaperones (not parents) on a schedule that means they spend a number of days away (staying in hotels with chaperones) and then a number of days home. While away during term time children are also tutored. Parents make and pay for travel arrangements for rehearsal, though many shows pay children a small travel allowance so some costs can be recovered. For touring, everything is arranged by the production and there is limited flexibility to depart from arrangements (understandably as it is a huge logistical undertaking). While touring the production pays for chidren's travel, food and accommodation.
Matilda tour is closing later this year so will not be recasting. Children rehearsed in London and travel from London to perform.
Les MIs tour - boys for Gavroche rehearse in London and tour with chaperones, but girls for Little Cosette and Young Eponine are cast local to the tour production, rehearse locally and live at home.
Annie tour - children rehearse in London and travel from London to perform.
As Mummy twinkle toes suggests, the forum notapushymum.com is a good source of information for parents of child performers.
