You can have a tenancy agreement under the Residential Tenancies Act 2010 (RT Act 2010) for premises that are ordinarily used as a holiday house, provided that the purpose is use of the premises as a residence (section 13). If the purpose is to occupy the premises for not more than three months for a holiday, the Act does not apply (section 8(1)(h)).
This is changed
The RT Act 1987 excluded both agreements for the purpose of a holiday (the period was not more than two months) (section 6(1)(e)), and premises ordinarily used for holiday purposes (section 6(2)(c)).
If your landlord wants the premises back for the holiday season (either for their own use, or to let to holiday-makers), they must seek termination in the usual way. Any additional terms that purport to require you to vacate during the holiday season, even if temporarily, are inconsistent with your right to quiet enjoyment and are void.