I would also agree that things could be partly explained by a growth spurt but not completely.
Are you confident about him 'looking like he still wants to feed' when he comes off? Trust your instincts. If when he goes back on after 6-7 minutes he is then feeding more slowly (e.g getting more hindmilk?) perhaps you should be encouraging him to go back on. Try the early winding idea at 5 minutes too.
Can I also say that going from 8 to 5 at your LOs age is AMAZING!
Many babies do really need a feed during that time so don't feel like its a step back if he does.
Night wakings come and go for lots of different reasons. Things are not always 'sorted' when you think they are. You can look forward to teething, developmental advances, and more growth spurts in the mix. Night wakings do sometimes happen more when something developmental is imminent. Could he be rolling? I like to quote this study:
Scher A. A longitudinal study of night waking in the first year.
Child Care Health Dev 1991 Sep-Oct;17(5):295-302.
Abstract: A longitudinal study of the development of sleep patterns addressed the issue of continuity and change in night waking in the course of the first year. Mothers of 118 infants, who took part in a follow-up study of normal babies, completed a sleep questionnaire at 3, 6, 9 and 12 months. Regular night waking was a common characteristic throughout the first year:
Baby's age % babies waking at night
3 months 46%
6 months 39%
9 months 58%
12 months 55% That's a lot of mums thinking their LO has 'gone backwards'!