Global warming ?

Last year in UK we had the longest warm and sunny summer since 1976. This year so far has looked set to follow, and the latest long-range forecast from our UK met' office 'threatens' 3 months of unusual heat to come...I can keep the greenhouse to a max of about 35˚C., but no less with my present set-up, in these weather conditions. ( usually about 20˚C. at night.)

I am having difficulties keeping my cattleyas properly hydrated - I fear overhead watering with a spray or rose on my watering lance ( water lodging in new growths is not too clever ..) I find some new growths shrivelled and burnt up - It takes me several days to water every pot ( about 500) by dipping etc, and I have only an hour or two per day to look after all my orchids .( I am the carer for my wife, who may be in her last days... I won't say more ).

Humidity is fine, 65-70% by day, and upwards of 90% by night, but still they are too dry - I suppose.....

They are potted in either straight bark, or those repotted over the last 12 months in bark/rockwool cubes mix, or those repotted in the last 2 weeks or so with an addition of shredded sphagnum moss. Maybe those mixes will be an answer, but maybe not.

I have done well growing oncidiums and many other genera in S/H in the past using an inert mineral compost - "baked clay pebbles" and think to try this with my cats. The trays of water, an inch deep, will surely lower root temperature, and could keep them wet enough. But what about resting ? How to keep that bit of moisture which they seem to need ?

Any experience, actual, not theoretical, please ?