Maybe if both sides restricted themselves to limited counterforce strikes, something like the opening part of Arc Light? Basically, the side striking first deliberately omits hitting civilian, C3I, and non-nuclear military targets, hoping to disable the others' weapons and then hold their cities and bases hostage to keep them from striking back. With a limited enough strike, it's not unimaginable that Northern Ireland could get off scot-free, since it seems unlikely the UK would keep nuclear bombs there. They've got some runways that would be attractive targets, in case V-bombers dispersed there, but there might be some way around that.
The problem, of course, is how to keep things from escalating once bombs are flying.