More than a month to go and already the event is full.

Unless I'm mistaken this was not the case in spring and generally at the full polaris events. Is there not then a case for having the facility to compete "summer" style at all events if preferred?

Riding summer style (without a tent, spare clothing and sleeping bag, or cooking equipment) sounds great until you get to the over night camp (at a location you don't know 'til after you start) and have to spend the night in sometimes sub-zero temperatures. The spring and autumn 'challenge' events are harder than the summer one and IMHO better for it. Please let's not make things easier just to attract a bigger turn out.

It's not so much the luggage but the trail
conditions IMO. 12h carrying a bike through
the mud isn't the most fun way to spend a
weekend, even without a rucksac.

Not sure what 'harder' means, both events
are 12h in two days, you go as 'hard' as you
can (or want to). In the mud, with luggage,
it's definitely slower though!

It is not the style of the event but the location that has filled the event, lots of people live close to the peak and the travel times are resonably short.
Travelling in the UK on a friday to a Polaris is a pain but what to do?

2 day-overnight events are about team self sufficiency and traveling by bike...this is one of the few events that exclusively tests these skills. If you really wan to do 1 day events with comfy shorts in the morning and no decisons to make other than left, right or straight on then a years round of trailquests should do just fine.