Big recommendation for a new favorite! Timothy's home is a beautiful, comfy renovation of a Victorian cottage. The bedroom is spacious and light, with a very comfortable bed (I slept late more than once!). The kitchen had everything I needed to prep breakfasts, suppers, and hot drinks. The living room was a cozy spot to read on nearly-winter afternoons. In all, Timothy has created a warm and welcoming atmosphere for guests to his home, and he gave me lots of great tips for area sights, events, and eateries.
I found the cottage the perfect base for exploring London. Just a 10-min walk to the Tube station, then 20 min to King's Cross on the Victoria line.
When you've had enough of city central, head back to Walthamstow for a variety of tasty restaurants and relaxed village feel along the Orford Rd pedestrian area. My go-to stop after museuming all day was Hucks coffee shop - great coffee & pastries, a short stroll from Orford. The neighborhood around the cottage is quiet, and you may spot the local rogue fox. :)
Note on airport access: As of my visit in Dec 2019, Heathrow was a cheap 80-min ride ~ £3.10 using the Piccadilly & Victoria lines. Heathrow Express will only save you 20 min, requires several transfers & costs £24+.