Hi Brendan....that's interesting.
My proposal only works if the bank would agree to covert the mortgage on the one-bed (which has a LTV of about 60%) into a BTL....and then, at the same time, let me use my income to borrow a new mortgage for the bigger property.
I would have a c.50% deposit (from the sale of the non-mortgaged property) and the one-bed mortgaged property is in an area of high-rental demand, so probably a good BTL proposition, but my logic may be flawed or the bank may not consider it.
In these inflationary times, holding on to the property as an investment would seem like a good idea....and I like the idea of having something which will generate an income for retirement planning purposes....but no-one can say with any certainty.