One of the gardens I worked, in their conservatory they had potted Bouganvillea..it wasn't looked after that well but did managed to flower every summer. Then the owners managed to kill it by too much moisture and too low temps in unheated room during winter...that's when I 'stepped' in. I bought new one for them..potted it up into much larger pot and with 'proper' soil, that being more of loam based compost with added sand and grit for good drainage. I looked after the plant last 5 years and without wanting to sound big headed...it flourished and was truly beautiful thing. It was trained around simple cane supports and each spring just as the new growth started to emerge, it got good 'hear cut' to get rid of old straggly growth, mainly the spent flower heads. Although the plant did loose most of its leaves during winter, but because its roots didn't sit in cold and wet compost (just barely damp) it was able to take the low temp. In summer it stood near the open conservatory doors...sometimes getting almost baked by hot temperatures, but it didn't mind.
On one occasion it suffered aphid attack that came from other plant nearby..and it was lot of work to get rid of them.
I managed to keep the plant reasonably small too..with lot of winding around it supports I didn't allow it grow taller than 6-7 ft.
So, yes you can grow them in UK and successfully too, they just need some winter protection.
Go for it!