Thanks for all the good advice!
The tires do not look too worn and continue to provide good traction, handling and stopping so technically no need to replace them at this point. However as several have pointed out, I will be gone for 3 months and doubt I will wear them out but could rip a sidewall or something and then may be stuck. Think i will look for new tires before I go and stick the old one in my bike bag for the trip
Will check out the Michelins. Have been pretty impressed by the Ramblers but theres always an urge to try something new!