lets assume $18,000 per adult, with 2016 26 million over 20 adults in canada.  Further assume a average combined tax rate of 30% fed and prov.  (no idea if right but assume not far off).  Fed and prov programs like UI, CPP, old age security, welfare and other social that can be replaced total around $250 billion per year.  Basic deduction is around $304 billion @30% is $91 billion and all other deductions total around $200 billion @30% is $60 billion.  Add in reduction in govt salaries for reduced programs and it can work.   
Unintended consequences?  Incentive to work?  Other tax considerations?  how to deal with families with children?  divorced or separated families?  Obviously a lot of other considerations to look at.  But it is possible, it is not just a dream if looked at in the hard light of cost reallocation of govt spending.