The Baltics might take exception to the occupation.
http://en.wikipedia.org/wiki/Seven_Days_to_the_River_Rhine
The bigger question is, can Russia sustain operations for any length of time? More recent history tells us the answer is no.
The way to ensure that does not happen is to pre position American and other NATO troops and equipment in the Baltics and Poland.
Putin will have to greatly expand his Hide Russia’s Dead Program
And in doing so, softens up elsewhere for some yet to be identified country to exploit. That’s a lot of border Putin has to cover.