I concur with all the other comments here that using Vagifem twice or three times a week probably won't cut it if you've had that kind of bladder issue.
Personally I found that increasing my systemic HRT just created a rather uncomfortable level of vaginal 'wetness' but didn't do much for my bladder. It wasn't until I started using Vagifem that I really noticed a difference.
I regularly use it every other day with occasional (every few months) top ups where I use it every day for a couple of weeks.