Any useful answer to this question  must be taken in context, because it varies with the region and the species of plant. The plants you mention (and a lot of their relatives) grow and flower well where I live, and we never have freezing New England winters; in fact, except in regions where  there is frost we regard a temperature of 10C as pretty cold, and our summers range from mid thirties to mid forties depending on the region and the weather.

Any strongly seasonal plant depends on a combination of internal clocks and external conditions for clues about when to grow. Consider fruits such as cherries and apples; one has to choose varieties to suit your region. Some are frost-dependant. Too little winter frost, and their internal signals don't  work and their buds emerge at unsuitable times, some too early, some too late. We call it retarded bud. The tree needs a flush of ethylene to "break its dormancy", and to produce its ethylene it needs some suitable tissue damage. In a suitable area frost provides the tissue damage, but when the frost holds off, farmers in some regions spray the bare trees with harmful compounds such as DNOC, essentially a herbicide, once popular, but now widely banned,less toxic  naphthyl acetate compounds, amounting to artificial  plant hormones, and various other chemicals.

Such compounds jar the buds of suitable plants into reasonable synchrony without having to rely on winter chill. 

However, not all plants' dormancy relies on such traumatic signals. Some, such as cyclamen seem to respond to spring moisture, or perhaps a fixed period of winter drought; some are stimulated by seasonal exposure to light when other plants have lost their leaves, whether in winter cold or summer drought; it is not always easy to tell just what the trigger might be. Others tend to sprout when the temperature range or the day- or night length is right.

Given that the problem of dormancy breaking has been solved, some plants flower when the conditions are comfortable and favour growth, whereas others, such as snowdrops (and yes, some daffodils, crocus etc) steal a march by blooming at the first rumours of spring, sometimes actually with snow still on the ground. This has an extra cost in energy, but it enables them to avoid competition from tenderer species that might outgrow them later in the season. Some of them actually burn stored compounds in their tissues for warmth, whereas others, especially sub-arctic and alpine species (such as some poppies) are adapted to use the first barely-adequate sunlight of spring to warm their reproductive tissues and attract pollinators.

Of course similar problems apply to some animals as well. If they miss their associated plants or seasonal prey, that was that, as far as their reproductive prospects were concerned!

Sorry to be so vague. Let us know if you would like elaboration on some points.

Cheers,

Jon