Moving around the country with my employer hasn't affected which or whether I ride a recumbent. My commute in London from Kingston to Whitehall was on an upwrong, and convinced me I'm doing it badly. Mrs Wheels had a Terratrike at the time but I never took it into the city as one couldn't filter in it - essential to complete faster than the train. I wasn't bothered by lowness, it was the width. It was usable in and around Kingston, and saw plenty of use. Only ever saw 1 other recumbent in Richmond Park - a trike.
Since then I've had 2 (now 3rd) job in the cotswolds and one around Portsmouth. I only have 1 bike and it's a Cruzbike S40, previously an earlier & heavier & slower model from the same stable. So FWD. One *can* slip the front wheel but it's more dramatic event fallacy than a real hinderance1. Climbing doesn't define my choice of ride anyway. I've started using the old railway paths north and south of Bath a bit more since last autumn, and I do see other recumbents semi-regularly, and oddly enough more often than cargo or other speciality bikes.
The job in Portsmouth had a 6-mile commute and my old Cruzbike was ideal. Mrs Wheels' arrangements changed and she stayed with a trike, but a BIG upright Mission trike with a bench-seat. Usage defined that shift. What she'd really like, although wouldn't use it enough to justify it, is the tilting trike from Kervelo.
Also Castle Coombe race circuit lets cyslists go orbiting on Tuesdays during summer [daylight saving] time. There's a guy with a rapto-bike some weeks, and a tadpole tandem, but surprisingly little else other than me.
So I reckon suburbia is better for a bike under any circumstances, and not all 'bents are longer and heavier, but you need to know the market and what you want out of it. I think volume of people and trunk routes make it more likely to see them in London, but hang around the Bristol-Bath cycle path and they'll turn up too.
[1] I've done Bathford hill, Quarry Hill in Box, Colerne airfield NW climb, Bannerdown Hill and Winsley Hill in the dark and wet, so it's definitely possible.