I'm looking to book a trip from Paris through to Switzerland in late July. It looks like the most direct option with the least changes is Paris to Lausanne. However, when I go to book via the Eurail site it says that there are no seats available. No Eurail options are available for this timeframe on Rail Europe either.
I've looked through other options on the day, and no TGV options are bookable while one INOUI option is. The same seems to be the case for the surrounding days.
If I try and book earlier in the year, options are available for most tickets up until the end of June. Is there an earliest possible booking timeframe that I should be aware of? Looking online, some sources say up to two months in advance and that reservations are not limited for TGV Lyria, while others say three.
Thanks in advance for your help!