I don't even know how you would have a repeat wedding in the UK. You would be able to get a blessing in a church, but I can't see that the vicar would be willing to "now pronounce you man and wife" if you were already legally married.
I think this would depend on your vicar. If you are regualr members of the conggrgation and s/he knows you, they may be fine with it.
My cousin and her husband got married in a hurry becuase of a change in visa rules. In their case it was only a month or two. They didn't mention it to anyone and the wedding went ahead as originally planned a couple of months later. Their parish priest did both services and the second one (which I attended) was a normal marriage service, including pronouncing them to be husband and wife.
but you could certianly have a blessing, or , if having a second church ceremony isn't vital to you. you could have a separate ceremony with your own vows. (this might work quite well - you can tell guests that you have already done the legal buit privately (which would be true) and don't have to go into any detail about exactly when that took place.
I personally would probably o for the option of a quiet wedding now (this could be register office or church, as you prefer) then a celbration / ceremony when you are ready. I'd be inclined to be open with people about the fact that the ceremony has already taken place, if only because it avoids the upset which people may feel if they feel that they have been misled, and it means you don't have to worry about keeping your story straight.
Another option: What specific aspects of a BWW are importnat to you? Because you could try for a middle ground and get married now but on a budget.
Wedding dresses are expensive, but Oxfam have several Wedding Dress shops where you can get beautiful, worn once and ex-display dresses for very little, flowers don't need to be done by a florist, you can have a buffet rather than a full-service meal and so on.
I think the two mian issues people have with doing a wedding twice are:
1. It can look greedy, particualrly if gifts were given on the first ocassion
2. People may fel that they have been lied to or misled, if you don't let them know that the ceremony they are invited to is not the actual, legal wedding
I think that you can overcome (1) by not telling people the first time, and by making clear to anyone who does know, andwho does give a gift, at the time that you invite them to the second sceremony that they have already given you a gift and that they should not give another, and can overcome (2) by letting people know that the ceremony is not the legal one. This doesn't ned to be a big thing, you can say briefl (maybe on invitations) something about inviting them to celebrate your marriage, and sayingthat you had to hold the legal ceremony earlier for legal reasons, but want them to celebate your marriage with you.
Good luck, and enjoy whatever you decide to do.