I have been able to put more than 15,000 chars on the textbox where you can enter the number of hours/days/months/years and it appears that there is no control over that textbox. At the end the system closes the poll after 10 years as a maximum.
Imho that textbox should be limited to a maximum of 2 chars.
The general thing here is that we don't have limits on most form entries - the limits are enforced server side if necessary. It's only considered a bug if it's not handled on the server (and that is the component that would be fixed).