It’s so cool that you talk about names together! Lol, my family used to think I was so weird although now they’re more neutral overall. Aghhh, old and long names and uncommon fantasy names are such great categories and fortunately it is entirely possible for them to overlap! I’m not sure any of the following names fall into both categories (sorry for any repeats!) but I’ll give it a shot.
Zephyrine - you don’t love [name_u]Zephyr[/name_u] but this is a longer, feminine version of the name that feels very fantasy to me while possibly falling into your category of feeling older?
Gwyneira - okay this is just fantasy but I wanted to list it.
Winifred - old fashioned vintage name that has a definite fantasy vibe imo
Theodora - old fashioned but would totally fit a fantasy heroine.
Nimue - falls into the fantasy side but has a really cool sound.
Leonora, [name_f]Leonara[/name_f], [name_f]Lionora[/name_f], [name_f]Lionore[/name_f], [name_f]Leanora[/name_f], [name_f]Lenore[/name_f], [name_f]Lenora[/name_f], etc - maybe one of these spellings bridges the gap because soundwise it fits into both camps.
Philippa - again I think soundwise it falls into both camps and while it does lean more towards your preference this does have a very fantasy vibe, I think, and nickname [name_f]Pippa[/name_f] adds to both vintage and fantasy charm.
Georgiana - see [name_f]Philippa[/name_f] minus the nickname.
Wilhelmina - another vintage but fantasy tinged name.
Mirabel, [name_f]Mirabelle[/name_f], [name_f]Mirabella[/name_f] - totally fits both vibes.
Margareta - magical feeling variation of a timeless name.
Maerwynn - much more fantasy but nickname [name_f]Mae[/name_f] gives it a nudge in the direction you prefer.
Endellion - again more fantasy but could have vintage sounding nicknames like [name_f]Della[/name_f], [name_f]Dilly[/name_f], etc