You need to be hardy to walk 100 yards in the open air these days? Heaven help us! I have walked over that bridge several times in recent years late at night when food was available only on the other side. The entire motorway experience is bleak IMHO anyway, but I've got used to it.
Two of the next nearest services (Exeter and Bridgwater) are nightmares to reach (via massive busy multi-lane roundabouts with traffic lights) and the other, Cullumpton, is cramped and westbound usage is discouraged with no signs for it.
Only used Bridgewater a couple of times, but it's always been chaos.
On the M5 heading south, we normally pull off at Welcome Break Gordano, then keep going at the island and use the McDonalds in Portishead 5 minutes down the road!