The 3080 Ti has a peak power of 350 watts and with your other listed specs you are well under the 850w limit. Additionally, the Corsair RMX series is a great make/model, so you should not have any worries moving forward.
If a 750W PSU can take my 12700k and RTX 3070ti with 290W, then your PSU can easily take a 3080ti with 60W more. There should be no issues, really. It's a decent PSU brand and model, too.