Just answered your other post, being turned down for life cover does not necessarily mean you will be turned down for a mortgage. There is a system whereby a bank can allow (not all do) the applicants to sign a waiver in several circumstances, the usual being 1. if the house is not your principal residence, 2. applicants over 50, 3. person cant get life cover & 4. the cost of the life cover is prohibitive.
The disadvantage is that if anything were to happen your wife the mortgage will not be cleared off, but some banks will allow this especially if you are the main earner. It's not that uncommon, lots of people for various reasons get very high quotes for life cover that they cannot pay so it would not be fair to ban them totally from owning a home.