That's what I'm planning, too. Especially if LIS-TMS isn't full and I get an empty middle seat, I have no problems sitting in Y. On the way back, I'll ask at check-in at TMS if they sell upgrades (if it's one of the LR planes). I booked yesterday and paid 895 EUR for Y. J would have been 2500+ EUR. Wow!

The fare I picked included seat selection, and I was a bit surprised to find that the seats, from row 13 onwards, are supposedly not reclining. Does TP really have non-reclining Y seats on the A321LR?

Last time I flew TP was in January 2020 to Bissau, on a narrowbody Airbus, which came with green non-reclining LCC seats in the back and then a few rows of red, proper Y seats in the front, some of which were sold as J and some as a sort of Y+. It seems that my TMS flight also has these green non-reclining LCC seats, as well as an upsell opportunity to red Y+ seats. I would have imagined that a plane intended for longhaul would feature proper Y seats all the way.

As a sidenote, how early should I expect to arrive at the airport in TMS? If it's a small airport and there are no other departures at the same time, there should be no need to arrive superearly, right?