Just as a suggestion for something a bit different. Next year there are EDI-FLR flights Fri/Sat/Sun on BACF and I think that the May half term dates in Scotland will be different so there will be better availability. I think the EDI flight on the Saturday has the best times

Probably easier to get too than LGW/LHR and you can get the direct train from Piccadilly in about 3 hours or drive.

Edited to add on those dates it's Sunday only so out on 25/5 and back on 01/06 there's 2 J seats on both the outbound and inbound for it. The Sunday flight is 6.45am so would probably need a Saturday stay but at least FLR isn't an airport served by the budget carriers.