I too am in the Southwestern U.S.A. - Tucson, AZ. I don't know exactly how your weather is, compared to mine, but we are having some rain this Winter (that doesn't always happen), so in a month or so, we will have a small to medium Winter honeyflow from desert wildflowers. Earlier this season our only honeyflow was our most reliable one, the Mesquite - usually from mid-April through the end of June. But this past season it ended early, in mid-June.
My bees have been subsisting on the honey and pollen they harvested from Mesquite, plus a little Creosote Bush pollen and nectar which comes in almost continuously (Creosote Bush is also our usual Spring build-up source). Some hives manage to maintain good reserves, other hives are near starvation. Since I decided to focus on producing bees and queens, instead of honey, I began feeding pollen substitute whenever natural pollen is scarce. I also feed 1.5:1 sugar syrup (one quart at a time) to colonies that have used up their honey reserves.
I feed all my hives and Nucs with pollen substitute, but I only feed sugar syrup to those colonies that need it.