I'm not very familiar with the Ryobi, but the basic physics I'm sure hold true for any like inverter generator. In part it might depend on how you are planning on using the genny, but from experience, the overall power loss is not "huge". Noticeably reduced.. yes.. but I wouldn't re-jet unless I was going to be continuously at altitude.
If you are just looking to recharge your batteries, you'll be fine. If you plan on running any high load appliances on-gen then you might have an issue.
Easy fix though.. go solar!