So I saw some youtubers who had an upscale for Naruto to Low Multiversal - Multiversal+ range with inaccessible/immeasurable speed and I think it sounds pretty right. I will try to repeat what they said and use the scans they gave: Base Naruto was breaking the universe with small amounts of his chakra which means at full power he would scale to universal+ (because at full power he will break the whole universe completely). Not only that but he was also breaking other dimensions like Kaguya's which one of the youtubers scaled to be universe in size via "sekai" statements which means world or universe. They said the sekai in here talks about world in the meaning of universe because Kaguya's dimensions contained stars and moons so it can't be world in the meaning of planet only. This would scale Naruto to low multiversal. Momoshiki had same statements as Kaguya and stars in his dimension too which would scale his dimension to be universe in size too. One of them also showed scans of Momoshiki having infinite amount of energy, which means he would be able to create infinite amount of universes which would give him Multiversal+ scale. Naruto is more powerful than Momoshiki so Naruto would scale to that too.
Now for speed: Base limiters Kawaki was moving in the daikokuten dimension which was stated to be timeless, this would give him inaccessible speed. As they said there is no proof it's resistance and not their speed. Naruto is as fast as Base Kawaki because he is as fast as base Boruto because both dodged the sukunahikuna rods and base boruto is faster than base limiters kawaki. This would give boruto and naruto inaccessible speed too. Moreover, kid karma Boruto was able to move some organs in stopped time which they described as "nigh inaccessible speed" (scale is ok but the name they gave to it is terrible ngl) and naruto and boruto are way faster than kid karma boruto. They had one more proof showing kaguya's AKAB were stated to move beyond time and space and since SO6P Teen Naruto dodged them, this would give him inaccessible/immeasurable speed.
They explained why the scans are canon and all of that.
So conclusion: Naruto: Low Myltiversal - Multiversal+ with Inaccessible - Immeasurable speed.