In the first episode of “Too Much,” Lena Dunham’s loosely autobiographical new series that premieres on Netflix this Thursday, Jessica (played by Megan Stalter) arrives in London from Great Neck, N.Y. She is subletting a flat in the fictional Hoxton Grove Estate, and expects to find verdant grounds surrounding a stately building, like something one might find in a Merchant Ivory production.

“Good luck with that, love,” the cabdriver laughs as he drops her outside an apartment block with peeling paint. After all, the Britain we see onscreen — in period dramas or in modern Richard Curtis romantic comedies like “Notting Hill” — tends to emphasize a certain aspirational loveliness. It also tends to gloss over details — like the fact that “estate” can refer to both sprawling mansions and public housing.

This well-established idealization means that when Jessica first meets Felix (Will Sharpe), an indie musician inspired by Ms. Dunham’s real-life indie musician husband, Luis Felber, he quickly hypothesizes her reasons for being in London: “Let me guess, you’re one of those ‘Love Actually’-loving girls?” he asks with a grin. “You’re on a pilgrimage?”

While the British pilgrims fled to America’s shores about 400 years ago, Ms. Dunham, who moved to London in 2021, is one of the many Americans making the reverse journey today, seeking refuge in the coziness they have seen depicted onscreen or on the page. But as these Americans adjust to regional accents and codes of conduct, many are surprised by what they find. “It didn’t take long for me to understand some of the decay underneath the facade,” Ms. Dunham said in an email.

Dating Was ‘Hell on Earth’

Adrianna Cordero-Marino, who works as a consultant in the health care and pharmaceutical industries and describes herself as a “big ’90s rom-com girlie,” was so excited to start dating in London, she changed her Hinge location a week before she moved from Ambler, Pa., in late 2020. She liked the idea of finding a “quintessential cute little British boy” in the mold of Hugh Grant’s William in “Notting Hill.”