So quick Grobag update - it worked ok on Friday evening until DS threw up all over it on Saturday morning lol. Worked out well Moggle with the travel mat to change during the night and he felt warmer in it although had to be careful to spread it out when he was in his crib so he could kick his legs. Will persevere with it I think despite him having a rough nights sleep I'm putting that down to his jabs he had the same day.
Had a horrible night last night I went out for dinner with some girl friends leaving hubby to do the last feed and settle mini mama. Turns out DS guzzled 6oz EBM and hubby topped him up with another 2oz of formula (which he hasn't had since hospital!) So despite coming home to find them both sparko it didn't last long 
DS threw up at midnight and I mean it was a river flowing from his mouth sick worst I've ever seen it went everywhere even soaked through the mattress! He was the palest I've ever seen him too and slightly blue around the mouth and eyes (poor little mite!) and kept throwing up. Managed to get him all cleaned down but he was fast asleep so not very responsive and breathing really quietly and slowly so I panicked and rang 111
They got a GP to call me back and she reassured me which at 2am it might be a combo of the milk and jabs was just what I needed as hubby was walking the floor profusely apologising and beating himself up that he'd given him the formula 
So after been awake most of the night just watching him sleep checking he wasn't sick again or chocking, and still breathing i'm cream crackered!
DS on the the hand is the perkiest I've seen him for days and was very hungry this morning. Phew! Feel like such a neurotic mother in the cold light of day though. We've had Los of cuddles and kisses this morning though so hopefully tonight will be uneventful and he goes down for a decent nap soon so I can get a few zzz's!