If you want standard airline Y service on FR (minus the meals), get priority boarding. Then you'll be all sorted with the carry-ons. Do be aware that when it says "gate closes 30 minutes prior to departure" they mean it, especially if it's a bus gate.
Leg-room wise, their standard seat leg room is better than Iberia's.

BTW. VY also offers this route. Also a semi-LCC, but closer to a conventional airline than FR. Bookable using IB avios if it's too expensive $$-wise.