if he is really distressed and finding it hard to breathe, plus blue lips etc (it can happen, used to with megs....she used to go into hospital a lot with it), then 999 for you.......you live quite some way from an A&E I would have thought.
you can call docs out during the night.....I have many a time, and they never mind. only thing is, it can take a while, and they normally ring you back before coming to see if he is really needed IYGWIM.
for mine I use calpol and nurofen plus lots of steam. sitting with them with their backs against you so they stay upright is good.....many I night I have wedged me into bed so that J can sleep against me upright and I can doze too. also that way you can breathe with them......I try to match my breath timing with whoever is the poorly one. kind of helps them to listen to you in a funny sort of way. might not be a medical reason behind it but for me and mine I have found it helpful (MY MIL suggested it as DH used to suffer really badly as a child too.....seems to be a family thing!)
hope he and you get a better night, but never feel bad for calling the doc out.
ooh.....almost forgot.....taking mine out into the night air also helps. very weird, but the amount of times we have headed to A&E and it has calmed them down.....the docs always say it is the night air!