Sorry - RY grounded only 7 STN aircraft last winter, partly to try to 'discipline' BAA (who was radically increasing STN per pax charges, as permitted by its regulator, the CAA), and partly to reduce winter losses on seasonal 'sun' routes. Since then, fuel has risen by $60-80/bbl (depending on which month you pick), so the rationale NOT to fly a/c in the loss-making winter is even larger.
Secondly, $130/140/bbl fuel is, in my view, much more of a worry for long-haul airlines, simply because they are up there burning the tripled-price Jet A1 for 10-12 hours, not 1-2. LHR/SYD should sell for at least £1500 round-trip to cover the average cost per seat, but was recently on sale at circa £600 - so the base fare needs to DOUBLE in order to cover today's average cost. What will demand for seats do when the price is doubled? Collapse. Even if J travellers are not price-sensitive, the back of the bus will be very weak, and flights will start losing money because the economy cabin will no longer cover its direct average costs.
And what does Joe Public do when SYD/HKG/LAX etc become too expensive? He still takes his family on hols, but will go short-haul, not long-haul, to avoid the high fares. So, in my view, LCCs get some pax trading down into their market, replacing the pax who can't afford it at all.
I'd therefore be more worried about the long-haul business model than the LCCs' model at $130-140/bbl oil combined with recession. Even $100 oil and recession would be a huge problem for long-haul leisure travel. Read the financial press - that's not a wacky theory, it's consensus thinking.