https://www.google.co.uk/amp/mobile.reuters.com/article/amp/idUSKBN16320N
Boeing investing 20m in UK factory.
Along with many other investors despite Brexit.
If these guys are confident about the UK post Brexit with all their analysts and forecasting, then I'd prefer to follow their projections.
Also I've read that Brexit is very unlikely to happen in 2019, unless all EU states agree on everything and every policy...which knowing our politicians that is very unlikely to happen..ever..