Not sure what to do...we will want to take a train from Nice to Lyon. I do know the date now, but it's too late for prems. Can I wait till I get to Nice and just go to the station..or will it be impossible to get.We would get senior rate.

It is not usually a problem, most trains have some available seats. But I suppose if you wanted to travel on some really popular holiday (or ending of a holiday), all seats could be filled in advance.

I don't like buying tickets at a large station, especially this one due a bad past experience having wait a long time to get an advance ticket.

So this time, I picked up my ticket at an SNCF boutique on Rue de la Liberte? instead, no wait.

Even though the PREM tickets are gone, you should be able to book regular tickets online at sncf.com. Choose the option of picking it up at a station or ticket boutique. Just be sure you have the confirmation number you will be given and the credit card you used when booking the tickets.

Tim has a good point that didn't even occur to me -- if the PREMs are gone so you need a regular ticket, you'd have to buy that online or in person, anyway, so what's the difference? As long as you know a specific time you want, of course, but it sounds like you do, so you can buy it online just as well as you could the PREMs. They have fares online for the decouverte senior price, so I assume you can do it.