You could always get someone medically trained to stick a tube up you like they do after the 'old man's operation' in hospital.
Is this something I have to look forward to in advancing years ? (he says feigning youth)
Not wishing to go off topic, but what is the 'dread' operation ?
And in an attempt to come back onto topic, after talking with a gent of more advanced years than myself (a total stranger actually, who I ended up discussing ..... the speed at which the need to tinkle seems to increase with age) he mentioned keeping an empty plastic bottle in his car. Just in case.
After not too much thought I saw the sense in this and decided I would likewise keep one as a sort of insurance: Which after the speed of need caught me out one evening (on the way back from walking in the Lakes
) - I realised careful thought was needed with the bore of this bottle. Ahem, this being more to do with margins for error than a brag ...
I guess fiddling around with a container in a tent/sleeping bag is similar to doing so in the drivers seat (while parked up I hasten to add).
I now drive around resplendent with an old Comfort Conditioner bottle in the boot.
Could be problematic with lightweight camping though.