Tend to agree with David, I'd be paying full desposit on a CC -> thus protected by CC and atol. -> and looking forward to holiday - I'm so desperate for a holiday right now (with 2 already being cancelled SINCE Mar) that we're even going to be going to the family caravan as soon as thats allowable under UK quarentine rules (which will be by July they seem to expect). I would expect it to fly from Heathrow on a newer plane on your holiday in Sept , and to be honest having seen the videos from the reopening of Las Vegas last night would expect a full holiday with a ton of fun in Orlando. The parks will be quiet and you'll get temperature checked, but having seen what Vegas was doing last night, and what is planned in Orlando I'd be happy going. If Mr Trump doesn't let you in, or the FCO still has advice against US by September I would be highly surprised. The Disney machine will reopen - the holiday will likely happen, and all will likely be a very nice holiday. What I personally woudlnt' be doing is cancelling deposit/trip as that is more likely to lose money. Me and Wife are considering a late booking to Orlando probably next month when we hear of what happens with first trips from July onwards on park reopening. (I know both myself and David have a timeshare in MCO, we'll probbaly be making 2 trips in 2020-2021 in my personal plans, and we personally need to go prior to next April to avoid losing use of a week of our points (the week we should have taken this April)). Orlando and Disney will be reopening, and in plenty of time. Universal/Seaworld opened this week I believe. VS/VH won't obviously be flying to Orlando until Trump/FCO change guidance, and it's safe for holidaymakers -> the risk of them being sued is very high otherwise. I expect personally that to happen early-> mid July.,
Ref: Quarentine on return, both myself and our family ahve been informed we're working form home until Christmas at least right now, so a 14 day quarentine on return ulitmately changes nothing for us.
If you are cancelling because of other covid related items such as losing job etc or just not wanting to go, I would obviously not be paying up -> that is a good reason to cancel, but you probably will lose deposit in such a case.