@CormorantStrikesBack Are you aware of the Youth Mobility Scheme (YMS) in the UK or the International Experience Canada (IEC) scheme in Canada?
From January a Canadian who is 35 or younger can get a three year work visa to stay in the UK. (It's currently under 30 and two years but it changes in January).
To be eligible he must be 1) Canadian 2) No older than 35 3) Do not have dependent children 4) have £2,530 in his bank account.
There is a £298 fee to apply for a YMS visa. People from many other countries including Australia, New Zealand, Iceland, Hong Kong, Japan, South Korea, Taiwan can also apply.
There are also reciprocal arrangements for young Brits to go and work in those countries. The Canadian scheme, IEC has similar requirements to the YMS except that you are only required to have CAD$2,500 (£1,460) in your bank account.
Details of YMS scheme here:-
https://www.gov.uk/youth-mobility/eligibility
As I understand things, the £38k figure includes income from both partners (see here https://www.gov.uk/uk-family-visa/proof-income)
So, as I understand things, he can come to the UK on a YMS visa for up to three years and get a job here. They can then marry and apply for his visa on the basis of both of their incomes in the UK.
Also, if your DD is saving for a deposit at the moment it may be better to put off buying a house as having cash savings reduces the amount of income you have to show.
For example, under the current requirement for £18.6k income if you have savings of £62,500 then you do not need to have any income at all. The figures change with smaller amounts of savings so, for example, if you have savings of £40,500 then the income requirement is reduced by £9,800 per year.
So, if that continues, then if you have £40k of savings then the income requirement will be reduced from £38k per year to around £28k per year.