Does anyone know any retailers that sell wider roller blinds that aren't made to measure? Need 240cm.

I've seen 210cm in Dunelm but that's the widest I've been able to find apart from some on amazon that are 240cm but no idea what the quality would be like and imagine it would be awkward for them to post.
I've checked everywhere I can think of but just in case I'm missing something before I accept defeat and go for a made to measure.
Thanks in advance!