Agree on skipping Wi‑Fi models - look for simple 2.4 GHz FHSS video units (or DECT 1.9 GHz if audio-only is fine) for stronger through-floor reliability. To handle outages and extend runtime enable VOX/eco mode, lower screen brightness, and choose a parent unit that charges via USB so a small power bank can keep it going; a spare NiMH pack is handy too. For range, mount the camera high, keep it away from metal like crib rails or vents, and place the parent unit a few feet from your router or microwave to avoid 2.4 GHz interference.
As a nanny I actually try to control the variables. Smaller portions warm more evenly than a full that model so I store milk in the amounts the baby usually finishes and combine only if needed after warming.
I always start with warm tap water in the reservoir and I let the that model sit for thirty seconds after a warming cycle so the heat evens out before I test. Swirl gently to reincorporate the cream layer and you will avoid those hot pockets.