Should I replace my 5 year old Sailun S637

[BruceinDFW]

I have a 2017 40' Montana with the original Sailun S637 G rated tires. They still have a lot of tread on them with no visible damage, cracking, etc. We have put around 10K miles on them in the last couple of years and are heading out in a June for another 3-4K trip. I'm trying to decide if I should replace them prior to the trip or keep them on for another year. Looking for community input. Thanks!