What would be the maximum time between the indoor warm-up and getting on the outdoor project, assuming that one is travelling in a warm car and keeping warm on walk-ins etc??
I even find light campussing the day before makes my warm-up easier when getting to the crag (esp. important if there isn't really very much to warm up on)
When at comps, on the rare occasion that i qualified, i only needed about 10mins to rewarm up and that's with about 4hours inactivity
it normally takes me about an hour or more to get proparly warmed up after a rest day or inactivity or whatever, so anything which can shorten this process is beneficial.