Travel optinions please

[Cindy <clb@micron.net>]

Hi Ridecampers,
I need some opinions.  I have an opportunity to take my horses with me
to Az (from Id) for 4 weeks in March. My husband's family will be
visiting in Phoenix and since there are two rides in Az during the month
I am considering
hauling our horses to ride in the desert and ride LD at both rides. 
This
desert riding during the winter has been a plan I have had for years.
It is about 1000 miles and a great change in temp 20 F to 70F for the
horses.
My main concern is the health of the horses and the vesicular stomatitis
reports in this area late last year.  I have cabin fever at this point
with the Idaho winter and need some sane advise as to whether I am
making a
rational decision.  I have had horses for forty years and have hauled
across the US numerous times, but I am newbie to LD and endurance.
Please respond to me directly with any advise.  Thanks Cindy