I don't agree with authors below on such factual situations being "probably quite rare"? Did I misapprehend something?
I'm thinking of a David-and-Goliath factual pattern, where an airline expressly labels a term "apparently insignificant to them" as a warranty (e.g. prompt arrival), but that they breach "in a way which exceptionally gives rise to very serious consequences" (e.g. tardiness causes someone a passenger to miss a wedding). In view of airline horror stories, this doesn't feel "probably quite rare".
It has been suggested (Reynolds, 1981) that the threefold distinction between conditions, innominate terms and warranties could be trimmed down to just two—a distinction between conditions and non-conditions. The breach of the former would always give a right to terminate whereas the breach of the latter may or may not, depending on the seriousness of the breach. In effect, this twofold distinction would treat warranties in the same way as innominate terms so that it would not be possible to have a term which can only ever give rise to damages. The question you might ask is whether the law should deprive the parties of this possibility of designating a term as a pure warranty in the sense that its breach will never give the innocent party the right to terminate. The issue is further discussed in Treitel at para.18-051 where judicial dicta to the effect that there may only be two categories of term are considered before concluding that the weight of authority supports threefold division and that this is preferable. Interestingly though, the very next paragraph of Treitel notes that ‘judicial classification of a term as a warranty is rare’. The important issue in practice is usually whether a term is a condition or innominate and the issue of whether it is a pure warranty does not arise. Most of the cases are, as in Schuler v Wickman and Hong Kong Fir itself, cases where the effects of the breach are not significant and therefore one party is arguing for a condition because that gives the right to terminate anyway and the other party is arguing that the term is innominate so that termination is not available on the facts because the effects of the breach are not serious enough. Whether all warranties are in effect innominate terms which could give rise to the right to terminate would only really be an issue where you have the opposite (and probably quite rare) factual situation of an apparently insignificant term of the contract (perhaps expressly labelled as a warranty) breached in a way which exceptionally gives rise to very serious consequences. It could be argued that the benefits of certainty involved in saying a warranty can never give rise to the right to terminate are largely illusory since if the consequences of breach were very serious, the court may well find that the parties did not mean to use the word warranty in this pure or restricted sense, just as happened in relation to the word ‘condition’ in Schuler v Wickman. If the parties really want to preclude the possibility of a right to terminate for breach of a given term, it might be easiest simply to say so expressly.