Things are looking more positive from the UK-end with travel to the US well-placed for government approval (subject to C-19 tests etc.). But right now, UK travellers are still on the banned list from the US perspective. Given the success of the UK vaccination programme and the rapid fall in infection rates, I'd consider the odds of the US easing restrictions on UK visitors by July to be pretty good. Apprehension concerning the 'Indian variant' seems to be key. But the airlines will need some reliable advance notice of government plans if they're to take on the risk of running Summer programmes. The nightmare would be more ruinous last minute bans and restrictions being imposed by squeamish cowardly politicians.