My DM started by switching to a cape and just allowing herself the occasional pack of cigs, each time she'd leave it longer between each pack of fags and soon enough she started to find that she thought she craved the cigs but then when she had them she didn't enjoy them at all... now she's not had a cig in about 18 months and that was after 40+ years of smoking 20 a day and she's started reducing her dependence on the vape also... not fully charging it so in the mornings she knows she has to use it sporadically or else the charge will run out before the end of the day seems to be working for her so far.
I'm doing the same now myself, I've been allowing myself for a couple of months a pack at weekends but the past month I've found the one pack will actually last much longer (I won't smoke any if I have some left come Monday morning) so one pack is actually stretching 2 weekends and even then it's more because I think I'm craving them and then actually not enjoying the taste once I've had a couple of drags.
I've also switched to menthol cigs so that when the ban comes into place, even if I'm smoke free by then (I really hope so) I won't be tempted back to smoking because the taste of a normal cig now is so disgusting to me that I'd rather not have one.
If I'm being honest though, the biggest motivation to keep me going has been how much less I've been spending... of course we know how expensive it is to smoke but when you actually feel the difference in the money then it can really spur you on to stick with it, especially when you're not having to go all or nothing, you've got the vape to help you through.
Good luck and I hope it works for you, but just think you've got nothing to lose so may as well give it a try... oh and make yourself get trough the first day or two as the initial getting used to it is where most people I know have given up, they say it makes them cough but I think it's because they're inhaling too much like a cig and it's different somehow.