I’ve never completely understood this, but I think the answer would probably be “no,” although I’m not sure. Usually when I leave the house I turn off wifi and just use mobile data (this is a habit from my pre-VPN days), although I guess I should probably just keep it on since using strange Wi-Fi with a VPN is ok (unless someone at Starbucks is using the evil twin router trick . . . ?). I was generally under the impression that mobile data is harder to interfere with than Wi-Fi, but I could well be wrong and my notions out of date. So, if need be, please set me straight. 🙂
HTTPS, sure. But your ISP can and will create a pretty comprehensive social graph about you using only metadata (server IPs or hostnames). Where I live, all home networks basically have a static IP. Also, besides a commercial incentive, ISPs are also mandated to log your connections. VPNs are not.