Should I switch to synthetics for a long trip south?

I use Rotella 15w-40 year round. I will traveling to Florida next week for 2 weeks and I will be pulling a 34' travel trailer. Would there be any huge advantage to changing to synthetic oil for just this trip? Like say Rotella 5w-40 for example? Or should I just stay with what has been working? I am wondering if the heat down south would be a good reason to change to the synthetic?

thanks,
greg

2002 Excursion 4x4 7.3