Must the Purim feast take place in a location where it's Purim?

Question

Somebody who is obligated to keep Shushan-Purim (on 15th Adar); must they eat the Seudat Purim in a location where Shushan Purim is being celebrated?

In other words, on Shushan Purim, can a Yerushalmi go eat his Purim Seuda in Netanya?

I can't think of a reason why not, since the Seuda is an obligation on the person, not on the location. Yet I cannot find anybody who specifically mentions it. (I've searched the Shulchan Aruch, Kitzur SA, Aruch HaShulchan, Kitzur Yalkut Yosef.)

However, somebody mentioned that maybe there's a lack of Simchat Purim if it's not Purim.

The same question & answer would apply to Mishloach Manot and Matanot L'Evyanim, I assume.

For Megilla reading it seems clear in Halacha (סימן תרפח:ה ) that you read in the location you are in:

בֶּן עִיר שֶׁהָלַךְ לַכְּרַךְ, אוֹ בֶּן כְּרַךְ שֶׁהָלַךְ לָעִיר, אִם הָיָה דַּעְתּוֹ לַחֲזֹר לִמְקוֹמוֹ בִּזְמַן קְרִיאָה (שֶׁל י''ד) וְנִתְעַכֵּב וְלֹא חָזַר, קוֹרֵא בִּמְקוֹמוֹ; וְאִם לֹא הָיָה בְּדַעְתּוֹ לַחֲזֹר אֶלָּא לְאַחַר זְמַן הַקְּרִיאָה, קוֹרֵא עִם אַנְשֵׁי הַמָּקוֹם שֶׁהוּא שָׁם‏

I'm looking for a source, either way, or else for a good reason why the Yerushalmi should have his feast in a walled city.

Answer 1

During a shiur about Purim the rav (who is a musmach of Ner Yisrael and gives a chaburah there) mentioned that all the halachos of Purim follow the halachos of listening to the megillah as far as the location difference. Thus, someone who is in the United States for Purim will have the seudah on the 14th, even if he is from Yerushalayim. Similarly if he is in Netanya, and not returning to Yerushalayim for the 15th, he will also eat the seudah on the 14th.

I just found the exact halachos of someone who is in one place or the other in פסקי תשובה edited by Rav Simcha Rabinowitz (my Rav provided the sefer and pointed to the correct area) starting at דף תקכט which goes through all the details and various circumstances.

דף תקלב סעיף ג contains tha halachos of someone who leaves Yerushalayim on the 15th. If he leaves after alos hashachar of the 15th (in which case he is chayav to say the megillah in Yerushalayim), but has not yet read the megillah, then he must read the megillah with a bracha even outside Yerushalayim.

My Conclusion This is analogous to the case in which someone leaves Yerushalayim after hearing the megillah but before eating the seudah. He would therefore be chayav to eat the seudah, where-ever he happens to be.

There are cases given in which he would be "פטור מכאן ומכאן" (Not obligated in either place) and other cases in which he reads without a bracha. This would have the implications for the seudah.

I did not have a chance to consider if the aniyim must be in Yerushalayim (so that they can use the money for Purim) or not. Similarly for mishloach manos.