A rose carer of a nursery once told me that the width of a rose bush is almost equal its height. Below are heights and other info for your roses. Hopefully, these info would help you to determine the pot size you should have. Good Luck!

Denver's Dream TM (SAVaden) (PPAF) Saville.
Named for the Mile High City, this tall, vigorous plant produces myriads of dazzling coppery-orange flowers. The color is unique, making this plant a great choice for adding a bright, eye-catching spot to the garden. Denver's Dream TM is easy to grow and extremely hardy.
Cultivar: Denver's Dream
Family: Rosaceae (ro-ZAY-see-ee) (Info)
Genus: Rosa (RO-zuh) (Info)
Additional cultivar information: (aka SAVaden)
Introduced by Saville 1994
Class: Miniature
Height: 24-36 in. (60-90 cm)
Spacing: 24-36 in. (60-90 cm)

Sachet TM (SAVasach) (Pat. 5967) Saville.
One of the most fragrant miniatures to date. Its damask rose scent fills the air. Spectacular in the garden, the lilac buds unfurl to double, flat, full-open blooms of lavender with bright yellow stamens. Not a candidate for Mini Queen, but a shoo-in for the open bloom class. Fragrant. Ht. 18-24".

Fairhope:
Bloom: Light yellow [ARS ly] blooms. Mild fragrance. 16 to 28 petals. High-centered bloom form. Repeats its bloom again later in the season.
Habit: Height of 24" to 36" (60 to 90 cm).