You mean your single stream of HTTPS traffic to a known destination 24x7?
What if you only use the HTTPS VPN when necessary, e.g. for streaming Netflix (seeing that they've been a target before), but for regular browsing, email, DNS, etc. you don't?
There are enough differences between HTTPS and VPN protocols to be able to distinguish them using DPI. IDS/IPS vendors even show this as a feature usually.
There's protocols like stunnel that hide your arbitrary TCP traffic in a TLS tunnel that looks like web traffic.