I’m a SAHM also. But my case it was easier cause my baby from was fridge cold breast milk (I was lazy one night and from then on she’s been taking cold milk 😅). If you don’t want to buy a portable warmer / in case nursing room doesn’t have hot water, you can just bring along your breast pump. Pump before baby’s next feed and feed directly after. For washing of parts (if you need to pump twice), bring along a small bottle of cleanser and your brush and wash outside. If you need to sterilise, use hot water from nursery (if any).