My thought: the weekend prior to SEMA and hosting at Sand Hollow (Hurricane UT)
Plenty of options for getaway overnight runs....day trips that can be challenging and/or scenic...some will already be enroute to Vegas for SEMA, which is only 2 hours down the road. Hotel and camping options abound, civilized or primitive...weather is good that time of year...doesn't interfere with Trail Hero, Southern Cruiser Crawl, BAJA or anything else I can come up with.
Moab is overdone. Ouray/etc is overdone (and super busy, having just been there). SW Utah offers a lot of options, and is VERY OHV friendly as well. 160,000 OPEN OHV acres to play on between UT and AZ.
Plus, selfishly, it's my backyard
2017 dates would end up Oct 26-29
2018 dates would end up Oct 25-28
2019 dates would end up Oct 31 - Nov 3