Florence goes beautifully with Henry.
Popularity varies so much from area to area. According to the stats, it's in the top 10 nationally and has been top 20 popular for quite a few years now, yet I don't know a single child with this name (and, working in a school, I meet an awful lot of children).
The 'old lady/man chic' trend doesn't tend to be big around me. Names like Florence, Elsie, Arthur, Mabel, Stanley, Albert etc, which are all popular according to the national stats, are really not that common around me. Yet, by the nature of the stats, that must mean there are pockets around the country where they are exceedingly popular for them to reach that high in the national stats. Around me, it's all Isla, Harper, Sienna, Mila, Aria, Maya, Luna, Arlo, Archie, Teddy, Finley, Leo, Oscar, Jude,Jaxon, Hudson... definitely seems to be a trend for more modern names or diminutives of classics here.
I wouldn't worry about the stats. If you both love Florence, that alone is reason to use it. Nationally it seems to be on a par with Henry and that didn't stop you using that. Coincidentally, Henry isn't one I hear a lot around me either. I only know of one, who will be 2 soon. Your taste for classic names hasn't caught on much around me yet (which is why my own children's statistically popular names, which are often dismissed by others on here for being "too popular", are also hardly heard around me). Yet if I'd have gone with, say, Lila or Eden for dd2 (both of which i liked and considered) she'd gave been one of many at her school as they're both much trendier than the classic we went for, despite her name being higher in the national charts. Dd2 has a top 5 name. She's still the only one in her school and I'm still yet to teach one at mine!