The next milestones to hit are:
* A 10x increase in generation capacity
* A 100x increase in storage capacity
* A 1000x increase in seasonal storage capacity
* Electrification of heating
* Electrification of synfuels and synthetic chemical feedstocks
Full energy sovereignty is achievable within 10 years at wartime-spending levels. Probably 30 years otherwise.
Rehabilitation of nuclear is almost certainly required for the transition and a very good hedge / backstop regardless.