Per this law.stackexchange question it's possible to use google analytics without getting consent and still comply with the GDPR.
I was thinking about creating two GA properties for a single domain name. One that switches off all the features that the GDPR requires for non consent and another that tracks users that have consented and have an account setup where they can make opt out changes, manage cookies etc.
Is it possible to track the same GA property / browser client using two different GA ids that correspond to the different configuration settings?
In other words when the user is logged in, the user gets tracked by the consented GA id, but when the user is not logged in and anonymous the user gets tracked by the GDRP compliant non consent GA id?
Yes. You just need to determine the technical identifier of a logged-in user (probably a cookie or js variable), then use that identifier to pivot tracking logic. If you have analytics.js or gtag.js hardcoded on your site, then you'll want to change your main embed code to have conditional values for the tracking id and anonymizeIp.
If you're using GTM you can use lookup tables with the logged-in identifier as the input. Use these lookup tables as the value for GA Tracking IDs or other tracker fields. If you're not using the GA Settings variable (which you should!), just make sure you set these config value in every GA tag.
Alternatively, if your primary GA Property can be otherwise compliant, it might be an option to track both consenting and non-consenting users in a single property, and pivot only the anonymize ip setting (analytics.js/gtag/gtm), not the GA tracking ID. It's possible to pivot advertising features tracking-side too.