Yep, that’s the key issue with indoor HPWHs in cold climates - they’re essentially “stealing” heat you already paid for. Modern split-system models with external condensers solve this, maintaining efficiency even in winter. They do need more power on startup though, so if you’re considering one check out power station options on gearscouts.com for backup during outages. The newer LFP-based units offer better $/Wh value for this kind of application.