Travelling in UK After Work Visa Expiry

I currently have a UK work permit (five year expiry) and therefore have a UK entry clearance to live here during that time. The entry clearance is tied to my work permit, which automatically expires as soon as I leave my current employer.

The plan is to leave my job sometime next year, and I'd like to spend some time travelling within the UK (I'm already here, so why not?) and I'm lucky enough to have squirrelled away enough cash to support myself during that time.

However since the entry clearance expires when my job ends, would I need to leave the UK (return to Canada) and then come back on the basis that visitors can enter for six months (as long as they don't work). Or can I "roll" my entry into a non-work basis from the date that my job ends, so I can remain in the country for an additional six months without having to depart?

Thanks for your help.