The South forced the issue. We will never know what Congress would have done because South Carolina and the rest of the South forced armed conflict on the issue.
Lincoln did everything in his power to wait for Congress to reconvene and address the issue. The South would have none of it. They were out for blood and got it.
As for land, the South was blocked by the Union. Texas was bordered by New Mexico, Colorado and Oklahoma all US Territory or States. And it was the farthest west State they had.
If Lincoln was trying to avoid hostilities he wouldn't have tried to resupply Fort Sumter knowing that the south would stop that from happening.
Once again for the stupid and insane. All Federal Forts were FEDERAL property. The fort in question was probably deeded to the US in the late 1700's shortly after the Federal Government came to be. South Carolina had no claim on it and had no right to blockade it. Nor any right to fire on supply ships supplying it nor the Garrison.
The South was preaching war through out the South as soon as the election process began for President. They not the North organized militias and drilled and armed for war. They not the North had daily editorials and stories about FIGHTING the North and of beating them. They not the North seized Federal property and stole land and equipment that did not belong to them. And still Lincoln refused to call up the Militia or increase the Army. While the South raised armies Lincoln did nothing but ask for calm until Congress could reconvene. He had ever right and RESPONSIBILITY to maintain control of all Federal Forts and Garrisons. It is the JOB of the President to do so.
Lincoln did NOTHING until the North was fired on. He had less then 16000 troops under arms and did nothing while the South raised armies, armed them, drilled them and trained them. You have not got a leg to stand on. The SOUTH wanted WAR. And they got it. And they paid for their own stupidity.
Because of that stupidity we will never know what Congress may have done. I for one am glad the South forced the issue. I suspect the Congress would not have done so. The South insisted on and forced war and paid the price for their ignorance and stupidity.