We went through a similar period recently (my daughter is 7.5 months old now & primarily breastfed still). During months 2 - 3.5, she only woke up 1 or 2 times a night & I nursed her. No problem. Months 3.5 - 6, she was waking up 3 - 4 times a night. We were all exhausted all over again like during month 1!
For us (every baby is different of course), what has worked was eventually realizing that as she got bigger & older, she needed to eat more! (Duh. I was so sleep deprived, no wonder I had no idea :-( .....And if/when she wasn't eating enough during the day, she wanted/needed to eat more at night. So I started all of the following steps to "night-wean" her and end the night-time wakings (....AND....lo and behold.....most nights she has been sleeping from 8 pm - 7 am for a month now.....fingers crossed :-)
1. being more conscious of how much she is eating during the day (she started getting distracted by everything during month 5 - now and without me realizing it, I think she really was eating less since she spent more time popping off the breast to look at other things than she spent ON the breast eating)
2. making sure to feed her more frequently during the late afternoon/evening hours (she generally nurses when she wakes up from her afternoon nap (at 4 or 4:30 pm) and then again at 6 pm and then again at 7:00/7:15 she gets her final feed (a bottle).
3. giving her a bottle of formula as her last feeding before bed (so hard to know how much she was getting with 100% breastfeeding...with one bottle a day of formula, I at least KNOW that feeding for sure how much she is getting)
4. she was still just getting a 5 oz bottle to go to bed (when she was getting up 3 - 4 times a night, and even as recently as month 5). I finallly realized she was finishing it very quickly and I wasn't offering her more! NOW (for the past month), she takes a 9 oz bottle to go to bed (!!!!) And I know it isn't too much because I make a 10 oz bottle and she never finishes that last 1 oz. She knows that she is full with 9 oz.
5. during the transition process, while we were figuring this all out & figuring how many oz to give her for that last feeding, and she was still waking during the night, we started sending my husband in to feed her with a bottle of either breastmilk or formula in the middle of the night instead of me breastfeeding her. We wanted to feed her, but also start making it as 'uninteresting' as possible and figured that dad with bottle was less interesting/desirable than mom with breast :-)
It took a week or so of getting all of this together but she started waking just 3 times (instead of 4 times), then just 2 times, then just once....then one night she slept 8 pm - 7 am and has been doing that for a month now. Daylight savings threw her off a bit for a few nights (she was waking around 5 am and talked to herself for about 30 min before falling back to sleep until 7) but she's back to 8 pm - 7 am again now most nights....and some nights she still wakes up once around 4, I nurse her and she goes back to sleep until 7:00 or 7:30 or so...
.....Hope some of these ideas could help for you guys.