No it doesn't, I am afraid, the tyranny of semi skimmed is upon us. Even CCR is semi skimmed. It's now quite tricky to get full fat at T5.

Inconsistently you may find Wiseman's full fat in one of the three WH Smith branches (upper level between North and South security, by Galleries South and at the base of the escalators at North - this seems the most reliable source but it's very hit / miss). Luckily for you (but not me) you have a baby with you, so you can take a bottle of milk with you, so long as you are prepared to drink some of the milk at security. The easiest thing to do is to bring a 1 pint of milk, in its original package, with you, and show it clearly to security as you come through. They don't like it in flasks. Don't rely on M&S in Arrivals to buy 1pt packs, they often only have larger sizes. Boots is now too small, and it only did semi skimmed and skimmed.

For the benefit of anyone searching for LGW: that's relatively easy, Boots nearest the BA lounges sells Cravendale micro-filtered full fat fresh milk airside, and they seem to keep good stocks of it. LCY: Haven't found a supplier.