Feb. in Vegas is usually nice, just cool in the day, possiblly windy.
As far as rides go, there are many nice places to ride..
Lake Meade, Hoover Dam, Valley of Fire, Red Rock, Nelson, Oatman, Good Springs, Death Valley.
A Little further north is wide open desert and scenery on the 93 and 95.
Las Vegas harley has maps for you, and they are decent descriptions of the rides..
Whatever you choose I think you will like it.

 

PM me when your plans are set if you rent. I may have completed my job transfer by then and be in Kingman, AZ about another hour past Hoover Dam, might me you at the dam? Group at Mother Road HD in Kingman schedule rides year round, should be OK. Might be "chilly", but more then likely not cold.