Show me the money - getting the travel budget together

Best ever op shop bargain: my 60 Degrees North jacket
sourced from the Reykjavik Red Cross shop,
being modelled on the Icelandic island of Videy

Heading overseas for months is an expensive business, even if one is a) retired with a pension, and b) going to inexpensive India. 

We worked out that our daily travel budget should be $85/day.

No-one has actually been upfront enough to ask this question yet, but an obvious query is:

How can you afford to do this?