In extreme cases you can flatten the pile which affects the warmth (but increases the windproofing). I spoiled a fleece like that a few years ago by keeping it in a compression stuffsack but I'm sure that fleece was different back in the early nineties. I would store the fleece normally between trips but I can't see any harm over a couple of weeks or so on a trip.
I've got as far as Edale without either boots, shoes, sandals or trainers before. I would have been able to turn round at the end of my street and pick my boots up but I'd dropped my mobile phone in the left boot "so I didn't forget it"!.
I'm now paranoid and use a 30m length of paracord to tie everything together at the packing stage...
It's a bit late but my favourite route in the area is Snake Inn to Fairbrook Naze, either walk along the NW edge to Mill Hill or if you are feeling fit and the weather is good cross the plateau to Kinder Downfall then along to Mill Hill. The plateau looks like the Somme on a bad day so take care and don't get lost!. From Mill hill follow the valley path (Black Ashop path?) back to the Snake Inn. The back end is less frequented than the Edale end so you might get a fairly solitary day if you are lucky. The lumpy bits north of Tintwhistle are a nice walk if you venture further afield but I'm less familiar with that end myself.