My bard will need to play for a long time. Long long time. Long enough that they'll basically collapse from exhaustion, as the purpose is to show devotion. Forced march rules seem to fit, so we can assume my DM will use an approximation of those, with CON+3 giving total exhausted play time of 8-12 hours (feel free to do exact maths) to reach exhaustion level 5 (speed 0). I assume I will need to roll performance at least once per exhaustion level. I would very much like to do that without disadvantage on performance.
My Valor bard will be level 10, and utilizing level 10 Magical Secrets is an option. This is a one-time event. My bard has relevant instrument proficiency, if that can help. Solution can be, but does not have to be, somehow getting advantage for all these rolls. Getting a specific magic item might not be out of the question. Multi-classing is not an option. Having allies provide help through the entire marathon performance would not fit RP-wise. It would be acceptable to negate disadvantage only on some of the exhausted performance rolls, if that is easier to achieve.
(Ask for more details and I'll add them here.)
In this situation, what ways exist to negate the disadvantage caused by exhaustion level 1 on Performance(CHA) ability checks?