I will be traveling to South east Asia for 15 days. My first landing will be in VIetnam Ho Chi Minh Airport. As a German Citizen, I am exempt of visa for a maximum of 15 days on a single entry.
I want to do a short visit to Cambodia. The problem is that those 15 days are allowed once and If I leave Vietnam I won't be able to reeenter. Therefore I am thinking about flying to Phnom Penh directly after landing in Ho Chi Minh. Would taking the connecting flight to Cambodia be possible without having to first go through immigration? (I travel with no checked in luggage).
If that is not possible, would a single entry visa for Vietnam be enough? I would use it once for entering Vietnam, and use my 15 visa free days the second time I enter Vietnam?