I don’t know about the water bottle holder, unless you could somehow use something like an overturned plastic bin for better stability.
I move my guinea pig between enclosures and I think it adds to mental stimulation and enrichment. Overnight I use a pet shop cage so if there is an emergency I can easily take her with food and water, rather than trying to catch her. During the day I have a 2x3 grid cage that I rearrange each day. Then a few times a week I set up a large grid play area on the floor.
Guinea pigs explore and remember routes and paths to run and be safe. Mine walks through and around everything forward and back so she knows the escape routes.
You would know if your pig were frightened or stressed, since she would hide and avoid contact. If she walks around exploring and if she’s eating, then she’s probably okay and enjoying the new surroundings.