I find this an interesting question. When we say things are impermanent, we often say that it is because they constantly undergo change. But in that, do we make the assumption that change will always be around and therefore that it's permanent? Could there be a place where change never occurs? Has this kind of question been pondered in Buddhist texts at all? The possibility of change never occurring?
Change is permanent.
The Laws of Nature (Dhamma) are permanent.
The unchanging Nibbana (Nirvana) is also permanent.
Buddhism explains only conditioned things (sankhara) are impermanent; thus conditioned impermanent things are permanently impermanent.
The Dhamma (Natural Truth) is permanent (but not-self).
This is standard Buddhism, as follows:
"All conditioned (sankhara) things are impermanent".
"All conditioned things (sankhara) are unsatisfactory".
"All things (dhamma) are not-self".
There is no actual condition that enjoys a moment's stasis. Consciousness comprised of perception and that which appears in and as perception can never fulfill the notion of a present moment and no possible moment has any duration.
That impermanence is all that can be found as present experience may suggest "change" is "permanent" and thus it is an insightful curiosity to ask if there is a place, or an observable perception, of "change never occurring" and this same curious demonstration of perception masquerading as experience/existence can also be said to be "change never occurring" with as much verve as you can muster "Change is permanent".
All that appears as mind in receipt of a find-able object or subject is the improvisational display of Consciousness, itself not a thing, and having no actual properties or implication. Thus, by the time we have conceived of something being experienced as change or otherwise, it is long gone, and yet does not cease even for a moment though there are none.
There’s permanency when one eventually achieves complete, permanent freedom from all the suffering and limitations of the physical body and after death, freedom from the need to reincarnate into yet another physical body. The permanency of a complete mastery over life, and death is possible, and with that one can one can even achieve absolute memory recall of every moment in this lifetime and even countless past lifetimes. Until the moment of Nibbana it is otherwise. The comforts of the day before disappear today the comforts of the moment before perish this moment. This unavoidable variation functioning with nothing existing permanent is called the' viparināma dukkha' (suffering caused by change) functioning in the nature of being and person.
Nirvana is end of changes. No efforts, no maintain, no continuous care to colloquially exist/survive, free from Sinkhara Dhamma which require continuous attentiveness to persist (Kaya Sinkhara, Citta Sinkhara).
The example of Nirvana is fire is extinguished because oil is depleted as well as the rope dipping in oil is burnt completely. The state of Sunyata of Nirvana also means there is no single entity left change or to be changed.
Whatever conditioned or arisen is in a flux of change and impermanent. Nirvana which is unconditioned and unborn is not in a flux of change or impermanent. The key here is if it is conditioned, if it is born, if it arises then it is subjected to change and cessation when the conditions sustaining it disappears.