You are exactly right — what is needed are democratic elections. Calling elections is exactly what the transitional president is required to do under the consitution. This is what he will do as soon as free and fair elections can be arranged. Unfortunately the CNE (the electoral board) in Venezuela is controlled the PSUV party (Chavistas), which means that, right now, it is not possible to hold free elections in Venezuela. For example, the election for the Constituent Assembly (the body Maduro created to circumvent the National Assembly) was declared fraudulent by the British company who ran the voting machines. From good, old Wikipedia:

“The electoral system of Venezuela is controversial. The Supreme Tribunal of Justice, with the majority supporting Chávez, elected officials to the supposedly non-partisan National Electoral Council of Venezuela (CNE) despite the 1999 Constitution stating for the National Assembly of Venezuela to perform the task.[3] That resulted with the CNE board having a majority consisting of Chavistas or those that supported Chávez.[3] Since then, the Venezuelan government controlled by the PSUV ruling party has manipulated elections, holding control of the CNE, the media and through government spending.[4]Following the election of Nicolás Maduro — Chávez’s handpicked successor — into the presidency, the CNE has been described as being pro-Maduro.[5][6][7][8]”

Juan Guaido is the leader of the only democractically-elected body in Venezuela — the National Assembly. Maduro stole the presidency in fradulent elections last year.

It is not a “few” expatriates — we are talking about the second largest refugee crisis in the world right now, somewhere around 4 million of them. And many more thousands who are cramming the streets of Venezuela in protest right now.

Fabiola Gonzalez and Guillermo Montero may have something to add.