if everything goes well and u have ur visas by January. If ur the principal applicant, u can do short landing in canada, stay there for 3 weeks to settle all the formalities needed like applying for ur PRcard SIN others that u shud and wud wish to accomplish with ur time. U can go back to ur place of origin , but since u applied for PR CARD and will receive it like after 2.5-3months,
U should have a canadian address
Of a relative or friend that u will write on the applicaionfo rm for cic will require it so they may be able to sed the PR cardin that address if prcard ready. Then ur relative or friend could arrange the pr card to be delivered to u in uk. U will not be able to enter
Canada again if u dont have ur pr cards with u.i dont know if there r other ways to enter without the prcards but i think u need the cards . U can read about the pr card appli in cic website ... Godbless u!