What are the best alternatives for a water bottle on the Reise & Müller Homage that has a Kiox?

[MarcL]

The handle bars on my bike already have a quad lock for the phone and a klickFix for the front bag. I could probably squeeze a bottle in there but it is already pretty crowded. I put a fidlock water bottle under the behind the seat lock, but it hits the fender when my weight is added to the bike.

I love the Homage, but I can’t believe such a high-end engineered machine did not put some sort of bolts or something for a water bottle. For now I will go with the one on the back of my Topeak trunk bag.