Assuming that you have a Schengen visa issued under Regulation 562/2006 (Schengen Borders Code) or one of its amendments and it has not expired etc etc then you would be entitled to enter any member state in the same way any other Schengen visa holder can.
Despite different terms and conditions applied when it is issued to each and every holder, there is only one kind of visa issued under the Schengen regime and there is only one controlling reference point (the regulation linked above and its various amendments, an example being Regulation 610/2013).
You wrote that your Schengen has an amendment in the 'remarks' section describing you as a family member. Accordingly, the border official would be entitled to be sure that this was still the case, so you would need to bring evidence of that. Your marriage certificate along with a note from the relevant EEA family member confirming that the relationship was still persisting would be fine. You mentioned that you wanted to bring a copy of the portrait page of your partner's passport. This is fine as additional support, but will not work without the other evidence.
Based upon your 'remarks' section on your visa, you might be able to use the EU queue. It's certainly worth trying if the queues are long. All that will happen is you'll be scolded and sent to join the non-EU queue.
All of this assumes that you have a Schengen issued by a member state. If there is a terminology issue and in fact you have a 5 year residence card (or family permit), then all bets are off. Those documents are issued under different regulations and the stipulation "accompany or join" applies. You did not include your status in the UK with your UK partner, so I mention this just in case. Be sure your visa is in fact a Schengen before setting out.
Per commentary, you can also refer to the Schengen Visa Code.