While I've departed T3 hundreds of times in my life it's always been for afternoon TATL flights. However I now have a BA 07:00 flight to Lisbon. I'll be staying at the Paddington Hilton to be handy for the early morning HEX trip. If I catch the 05:30 HEX will that give me enough time to check my bag in and get through security? I could carry on my bag if I run late but would prefer to just check it in on this trip as I'm in Row 1 and I'm worried I mightn't be able to stow it.